IMHO, the "grind" to earn or unlock things is what I consider playing the game. Ostensibly, you play a racing game to go racing. To get ahead in a game like GT/Forza, you have to...
go racing.
I understand some people just want to get straight to a higher level of racing, but that doesn't mean the rest of us are "conditioned" to enjoy working our way up. Besides, when a simulator does its job, the slower cars you drive at the beginning can be more enjoyable to toss around than a capable racecar on fat slicks. For me, anyway. I love the obscure little Japanese boxes in a game like Gran Turismo, too -- one of my favorite FFs in Enthusia is the Hondy City Turbo -- because they're cute and they're fun to drive.
It depends on the execution of the concept. If there's too much money to spend, it all becomes meaningless. Too little, and it becomes a "grind". In the end, whether you're hoping for a new car/upgrade or a little gold trophy in a checkbox, if you're playing to win, you're playing into the psychological reward of videogames. The reward, monetary or not, ought to line up with the effort required to earn it.
Personally, having access to everything can make a game a little boring. I routinely boot up old videogames I enjoy just to start from the bottom and unlock my way through the early stages of a game. In some games, that's the best part. I'm just hoping PCARS offers enough of a framework around my racing career that I can feel immersed by a single championship, instead of focusing longer-term goals like in GT/Forza (eg. what car to buy next). The problem with GT/Forza isn't the unlocking/credit system, IMO, it's the bland race formatting and AI that makes it monotonous to try to immerse yourself in every race. You
need other goals beyond winning.