If anything there was even more outdoor interaction in TBC than there was in Vanilla. Once you got to level cap in Vanilla that was it, you didn't have any reason to leave the capital except to go to a dungeon. In TBC they added the daily quest hubs that put both factions in the same spot which caused some heated player interaction on PvP servers. It wasn't until Wrath when they started to cut down interaction.
Well, I am not saying every single thing in TBC or in WotLK was bad, but the overall direction of them was wrong. Look at vanilla dungeons for example, like Blackrock Depths or Mauradon, these were huge, non-linear places where you had to have knowledge to even know where to go, and could find a ton of side stuff if you wanted. In TBC, on the other hand, the dungeons were basically short linear corridors, where you run through a few rooms, collect the loot, and leave. Wasn't TBC also when they started introducing instanced PvP? I might be wrong, it was years ago. And by WotLK, they had phasing and all that other crap.
The introduction of LFD (Looking-For-Dungeon) really crushed the realm community. It didn't help that they made dungeons the fastest way to level up, you could sit semi-afk in stormwind from level 15 to 85/90/100.
Yep, this I actually remember like it was yesterday. They announced the LFD tool, and it was so freaking OBVIOUS it would ruin human interactions right off the bat to anyone with half a brain. Before that damned tool, you had to actually either know people on the server, or message them from a server list, strike up a conversation, etc, and this would create all kinds of bonds on the server over time. After, nobody needed to know anyone else.
The reason I left "real WoW" is because I was always traversing through massive unpopulated spaces with nobody in sight. It became the dullest single-player RPG in existence. Fuck instanced content. It should never be even close to a main feature in an MMO.
Yeah, it was so crazy how much things changed from when I started playing WoW to around the time I quit (right before Cataclism). I have such awesome memories from the early days, most of which have to do with getting around the huge non-instanced world and experiencing it with other players playing on that server. Off the top of my head, there were certain dungeons with good loot that would be very hard to get to, before the damn LFD teleporter. You needed to get like 2 or 3 group member to the summoning stone to summon everyone else (I might be off on the numbers, was a long time ago), so I remember as an Alliance member, making the long dangerous trek on a PvP server through Horde territory (like the Barrens or those undead lands near Scarlett Monstery), just to be able to get there. That's what creates fun adventures and good stories, now it's just a bare Skinner box.