Well, they did a lot of this on purpose. They changed the physics, made it more difficult to make money, etc. and I think lots of guys are taking it the wrong way. It's just very different, people are used to making an easy 400k in GT5 from like 1- minutes, but in GT6 it's much more difficult. Many people who like the game to last a long time appreciate this, but fast-paced (like GT5) as far as earning money goes, don't like it.
It's tough to say, it's a great game, improved physics, more cars, better graphics, etc. so can't really see a reason to complain. I agree though, I like to compete in many different Online Comp's and it's a bit ridiculous how long it takes to earn money.