In the olden times when bands whom hadn't made it sticking to what they wanted to put out, record companies would pressure the band to go mainstream or they'd be threatened with getting dropped.
So, the aforementioned REO type moves towards ballads and more radio friendly music. There were dozens of bands who did this during the 70s and 80s.
But then record companies adjusted, more or less demanding this move right out of the box...then we started seeing bands like Boston getting signed. Bands whom had promotable material in the can ready to go. Also we saw bands like Asia and Foreigner where the record company had talent that had some track record that needed pieces of the puzzle put together to flesh out a promotable band.
And yeah, to claim Pink Floyd making this shift to survive is crazy talk. That was more of the band finding their writing stride with a record company that was willing to wait them out rather than a company pushing them or them consciously trying to become more mainstream.
