I appreciate your perspective. Luckily, the start-ups I’ve had the pleasure of designing for celebrate good work, as well.
In the end, an employment contract is a mutual agreement between two parties. It’s up to the employee (just as much as the employer) to do their research and make sure it’s the right fit, culturally.
As far as “side” projects, it’s my hope that most artists naturally want to create, and thus, spend many evening/weekend hours working on their own projects.
Scott Hansen (Tycho/ISO50) is probably the best working example of how to succeed (and enjoy) doing this.