I have played since mid-Vanilla and never unsubscribed... but WoW is getting more and more dumbed down.
In Vanilla many of the quests were challenging. Getting a max-level character was an accomplishment. If you were in an instance that wasn't severly low-level, everyone had to do their job properly or the group would wipe.
Since then it has gotten easier and easier. Leveling a character is a complete joke. My last two toon have gone from 1-85 only dying a few times. The pre-Cata instances are so severly nerfed that it doesn't matter what anyone does. Someone has to try to wipe the party for it to happen. None of this is challenging or interesting.
Queing for instances and raids has ruined the social aspect of the game. You no longer need friends or guildies. You can get a group whenever you want, with a bunch of people you will never meet ever again... who often treat you like they will never meet you ever again. The cross-server battlegrounds have harmed the game also. My faction used to be very successful in BG's, and we would see the same friends and enemies often. Now it is just a bunch of strangers on both sides, and my faction usually loses because the players in my "battlegroup" usually just farm HK's and don't care at all whether they win or not.
I still log in most days and play a little bit. And I know that I can do higher-level raids, arena, and rated BG's to be somewhat challenged. Still, I wish the dumbing down process would be turned around. One of my friends said that WoW has become the MacDonald's of MMO's, and I'd have to say that he's completely correct.
Simply not true. Blizzard has just made it easier to acquire epics, thus made players more powerful.
In my guild in vanilla, we would regularly demolish beginning dungeons for guild mates' alts. It was incredibly easy in epics and required very little organization on our part.
Take a group of T2/AQ geared players into LBRS/UBRS/etc and we cleaned shop like people in epics do in current heroics and 85 dungeons. It's just easier to get the gear because of LFD/LFR.
Same thing in TBC and WotLK, BTW.