This is exactly why. Perfect response.Community. WoW has grown in a lot of ways over the years, but at the cost of small tight knit communities that, as you said, made the game feel more "alive". Things like LFD/LFG/LFR/cross-realm bgs/servers being tied together, etc. have all taken away from the community in favor of ideals such as ease-of-life improvements and other shallow things that cater to more casual players.
And at this point in time that community feeling will likely never return to WoW. I realized that (and a lot of other things too) and thats why I am done with the game. I still find myself here for Diablo 3/Hearthstone stuff, but every time I see WoW related news I just don't really get excited. If anything, WoW at this point feels like WoW: 3 or something. The game really changed after the end of WotLK.
I know people will say "rose-tinted glasses" or something, but WoW truly was more fun for me back in 2007 when it was just Vanilla and BC. Everything seemed like a challenge back then. Leveling was way more challenging than it is now, and was quite time consuming (no XP bonuses/no heirloom gear), and max level content wasn't just readily available to you. You had to prove yourself worthy of doing the endgame content. You had to show your guild/PuG's you had what it takes to keep up with their raiding group. And if you didn't had what it took it meant grinding more dungeons, which meant grinding more heroics until finally you could start gearing up in Kara to do Gruul/Magtheridon.
And back then if you were raiding SSC/The Eye (can't think of the name, the one in Netherstorm)you were in a good guild. If you were doing Black Temple or Sunwell you were in the best guild (on your server of course). Now most all guilds are capable of accomplishing normal raids. Most are even capable of progressing a little bit on heroic raids it seems. There is no sense of "prestige" anymore in the game.
Anyways, I'm rambling. I don't like WoW for what it is today, and I know that it will likely never be what it was. I think nothing lasts forever and that WoW is getting into it's final years as the most popular MMO (it'll still be around for a while but something new is going to come up, whether it's by Blizzard or not).
But yeah. Those are my thoughts from from someone who played from the first half of 2007 to the late half of 2013.