Anyway, there's no such thing as 'better' worse' etc except in the mind of the beholder. MN has always had it's highs and lows. Personally I think 'AIBU' is a MN low and has led to a different vibe on MN. But clearly most people LOVE AIBU, and it gets most posts! So there's no objective truth about the state on MN, good or bad.
LOADS of things have had an effect on the site: size, mods / withdrawal of mods, intro or 'report this post', intro of member profiles, and, I think, the fact that since I was first on MN (back when you had a box for floppy discs on your desk!) Facebook and MSN have been invented. That leads to people getting to know each other off board in different ways, discussing threads and posters.
I used to have more in-depth discussions, and be in more consistent contact with certain threads. But it's me that has changed - I just use MN a lot less, have reverted to RL...and see people less, even though they are here.
And, um, aren't threads like this as bad as 'MN isn't what it used to be'??