Most researchers don't work for universities, and all limiting places would do is reduce the amount of talent in the industry. I used to work in drug development ( and hope to again soon). The people in the industry generate the funding through the ideas they develop. Less people working on novel leads means less funding which means less new drugs which means less successful leads to make the money for the returns on the venture capital which makes venture capital less lucrative which means less funding.
We don't make great money (and I'm an RA, not a scientist), but most are comfortably middle class. And like a good therapist, a good scientist isn't in it for the money either.