To me, buying stuff is what kills the game, now there's no point of focusing on production, just make a lot of trading posts, get a lot of money and buy whatever you want any time.
Did your enemy got a huge army next to your borders? No problem, go shopping and buy a nuke .
So I'm sticking with my whip, dear, I don't want to play The Sims.
Dude, buying stuff is super-duper expensive. It makes sense to have at least a couple of heavy-production cities for units (on standard maps). And then, yes, spam trading posts everywhere.
Sounds vaguely familiar right? In Civ4 the process was nearly identical (replace trading posts with cottages) and was known as 'specialization' and everyone said it was a great innovation.