One of the things people found disappointing about King Sombra was that he died at the end of his second episode. "Now he can't redeem himself for what a lame villain he was!" "He didn't get enough lines or screentime!" "GAK will always have more screentime than him!" "We'll never know more about his character!" Like Chrysalis, many believed he survived because they wanted him to, saying he could regenerate from his horn, and raged when Meghan McCarthy ended any further speculation by confirming his death.
But was that really such a thing to rage about?
As addressed under my Villain Complaints blog, main villains don't typically last past 2 episodes. Nightmare Moon and Chrysalis are presumed dead even if the latter has a slight chance of return, and both return in the comics, but of the four main villains, only Discord returned in a third episode, and the episode was about reforming him, which they do. As I knew they would but most thought he wouldn't be because they wanted him to stay evil and felt it would ruin the character. Let Discord's redemption be a one-time thing, many including Lauren Faust (and excluding myself) were disappointed by it. Let all other villains appear in only two episodes, and get atleast a presumed death in the second. That's the unique style of MLP is to only have major villains in two part episodes at the beginning or end of a season. His "being a lame villain" is addressed unber my King Sombra vs. Sauron blog.
Now, on to the matter of the actual death of King Sombra. No offense, but you're complaining that a "lame" villain was killed? That the "worst villain" in the show is dead and has no chance of returning? Imagine what reaction would be if it was Chrysalis that got disintegrated! Sure, she was most likely killed from the fall comics aside, but they could always have her return with Team Rocket immunity if they really wanted, and do in the comics. And I could expect an explosion if Meghan were to confirm Chrysalis fell to her death. Imagine if in his third episode, Discord was turned back to stone and either fell into a lava pit or got smashed to pieces. People would complain, now Discord can't return. So which would be worse for people who want villains to keep coming back - killing off Discord or Chrysalis, the two "best villains", or killing off Sombra, the "worst villain"? Suppose Discord had died and Sombra had turned good?
What did you expect to happen to Sombra at the end? Turn good? Can anypony imagine that? He's pure evil. Reimprisoned in the ice of the arctic north? He'd just curse the Crystal Empire again, and if it were as simple as that Celestia and Luna would have done it again. Sent blasting off like Chrysalis? I should think he'd return rather quickly. Left off a Karma Houdini? Get real. The more I heard and saw about him I knew he could only be destroyed in the end, even though seconds before it actually happened I braced myself for a mere "turned to shadow" like in the flashback.
And they really needed to kill at least one antagonist, too. G1 did it twice, and while it may not have been the little girl show that G2 and G3 were either, Friendship is Magic was more widely known for being the departure from that and is infinitely better, I never even knew about G1 until I read about Tirek. Until Sombra came along, some thought FiM was afraid to dispose of villains the way G1 did, saying G1 was more hardcore. When Lavan was killed in G1 (and he was the second, after Tirek), somepony was quoted as saying:
I can't believe they killed a villain on-screen! They blew Lavan up into chunks! Not even Friendship is Magic can brag about villain death, because either the villain gets sent to the moon, turns good, runs away, or gets turned to stone. More proof that Gen 1 is badass. Posted before Sombra blew up.
Apparently Nightmare Moon didn't count, since she outwardly seems like a corrupted Luna rather than a manifestation of her dark side (and many view her as the former); Windigos didn't count as they were beasts rather than characters, and depicted in a flashback; and Chrysalis didn't count because we're not sure she's dead, many believing she survived (if only because they want her to). Sombra was flat out vaporized onscreen, even if it drew debates that Meghan had to break up. Nightmare Moon and Chrysalis were sort of going along those lines, maybe to be subtle, but too subtle because nopony thought much of it, Windigos more direct but like I said they were voiceless one-episode beasts (and that windigo howl at the end might convince some that they are still alive). With Sombra they just decide to stop screwing around and kill him up front. Maybe she made him a flat character with little screentime and dialog so nopony would miss him.
I hope the rage mentioned in the first paragraph doesn't discourage Hasbro from doing it to the next villain, especially since it's bound to be spectacular like most of the Avengers villains
And also, just the fact that Nightmare Moon and Chrysalis are presumed dead as well (though not by some of the fans) doesn't give them much over Sombra except a slight chance at return if the creators really want to bring them back, and a return in the comics which can be canon or non-canon if you want them to be but isn't quite the same as an appearance in the show. Nightmare Moon wasn't noticed much because a.) She was the first villain, and b.) As previously mentioned, was implied by the episode to be Luna corrupted before Lauren Faust made that comment about Luna "no longer being present". Chrysalis, well, read The Fall of Queen Chrysalis for details, in short they probably didn't intend a return and intended to finish her Disney style. I know an anon has argued Nightmare Moon and Chrysalis at least have slight chance of return while Sombra is dead forever. Though I do not think they'll return in the show.
But look at it this way - Sombra may be the only main villain who's 100% dead, but Discord's the only main villain who's 100% alive.
Has anypony ever considered using this as one of the things to convince people that this isn't some little girl show like the last two generations stereotyped the name? Either convincing a skeptic or explaining the phenomenon to somepony for the first time? "Oh, and by the way a unicorn is graphically killed in the first episode of the third season." Sure, it happens with many Disney villains in movies that kids can watch, some in a less family-friendly way than Sombra, but that should atleast convince people that MLP is on par with them as an all-audience show.
Besides, it was such a spectacular and amazing scene, and I know a few agree with me there.
(How many times did I say "spectacular"? I wonder if Rarity's jumped up above Rainbow Dash as my favorite pony simply because I feel bad for her in Season 3 and the comics)