the choice was between mosaiced movies where you could fake being f**ked and uncensored movies where you had to put up with the physical interaction - and accept less money than in the mosaiced movie
But that's not the case anymore.
It's just simply economics. It's cheaper to produce and sell videos domestically (ie: within Japan) than it is to spend extra money in order to export it outside of Japan (overseas business legal fees, registration, billing fees, etc). Accordingly:
1) The vast majority of JAV makers make JAV for domestic distribution, while exporting producers are in the minority. So already, if a girl picks a producer at random, she will most likely end up doing censored work.
2) The money that domestic JAV makers save (from not having to export their material) gets fed back into their recruiting system, giving them more resources to scout out top models.
In reality, there are plenty of pretty actresses in uncensored JAVs (a number of them making the jump from the chaku-ero genre). But because almost all of their work is advertised solely
online (for international online sales) rather than traditional campaigns like DVDs, posters, and events (because you can't sell uncensored in Japan in the first place), very few uncensored actresses are considered A-list actresses in the JAV world.
Famous actresses who have moved to uncensored are indeed mostly due to losing their popularity, while some may have simply been offered a lot of money to go uncensored
because of their popularity.
And don't forget, there are a number of actresses who do
both censored and uncensored videos, under two (or more!) separate stage names.