World of Warcraft is popular because it's already popular. There are only so many people who play MMORPGs, and those people all have played WoW already, and their friends all play WoW. It doesn't even matter if the new MMORPG that comes out is a better game than WoW, because it won't have the playerbase of WoW, and that's why people will stay with WoW. It's a self-perpetuating cycle.
As for Skyrim, maybe they patched some things I didn't look at since I haven't been paying attention for the past couple months, but basically, out of the box, every skill besides the armor skills were utterly broken from a game balance perspective (Hey guys, look at me kill a bonus boss in one swing with my 10,000 attack power weapon!) (Hey guys, watch my stealth skills as I sit on the head of a guard in broad daylight without being seen and pickpocket him naked!) and many of the game features were placeholders at best.
Congratulations on getting married to a random personalityless NPC. Enjoy your three lines of totally generic spouse text repeated forever and daily pie.
Yay for the new "endless quests" I can get from the thieves guild that involves breaking into the shack of a peasant who apparently either made their furniture themselves when they were drunk or stole it from the "failures" heap of a real carpenter, and have nothing more to their name than some rags for clothing, wooden spoons, and a single loaf of bread, but somehow suddenly have golden candelabras for you to steal. They will be completely unguarded and provide absolutely zero challenge for you even if you don't bother stealthing at all.
But don't worry, there's the scripted quests that you will probably accidentally complete when you randomly wander into a cavern and pick up some random bauble and have no idea why you're suddenly on a new quest, only to find out you've just completely skipped all the good parts of the quest that provide any meaning or context, and just have to report in that bauble to the lost-and-found.
Plus those other caves are basically linear dungeon crawls that essentially involve a set of enemies that are too weak to be even proper punching bags leading up to an arbitrary boss fight that, if those punching bags before provided any challenge, will now be basically impossible to fight "fair" against, meaning that you have a choice between being bored through 90% of most dungeons, or exploiting glitches to survive the bosses, and being bored the rest of the time.
Yeah, there's room for improvement, here.
I'd also point out that basically everything that was done between Oblivion and Fallout 3 and Skyrim was basically "just try to add as much of the fixes that modders did to Oblivion into the vanilla game as possible." In fact, remember Oscuro's Oblivion Overhaul? Yeah, after that, they just plain hired Oscuro to work for Bethesda. That's not really a complaint, if they can't do anything better, that's at least something, but one would think that having at their disposal total artistic control would have led to something better than the utter placeholder that was, for example, the marriage system. But oh no, they just HAD to release on the utterly arbitrary 11-11-11 release date instead of actually shipping a finished game.