Well bending their minds is not the issue whan you need them. The issue is when you don't need them.

They make a mess and you have to make sure they are fed or they will destroy your lab. Constantly controling them gets exhausting. And don't talk about you proprietary mind control stones. They never work as advertised and just lose connection so you have to restart the whole mind controll process on some rats.

Just more hassle than it's worth honestly.