On normal mode, this was the case, at least around launch; heroics were a different story. That might have changed with subsequent hotfixes and the proliferation of raid gear, though. When I was playing though, running places like HoO or Stonecore on heroic in all dungeon blues without a guild group was next to impossible.
First, on a sidenote, I refuse to run HOO or Stonecore, they are just too annoying, but most of the new heroics are clearable with people who are mostly epicced out (and no I don't mean PVP epics) and aren't retarded. Assuming everyone's DPS is good you should be able to zerg through everything. And yes I've quit, but even before I quit they did make alot of the heroics easier, the first boss to SFK comes to mind.

As far as other stuff besides running in circles, running BGs gets kind of useless after you have all the BG gear and I don't see a point to rolling an alt or doing dungeons seeing as it doesn't improve my character, but like you said, that's probably just me.