I always felt like seeking input from employees, especially those who have contributed significantly and that you value a lot, is extremely important, but it's not necessary for them to have board seats and votes to consciously take steps to obtain their feedback and make good use of it.
Since participation in a company is entirely at-will, what's wrong with "Join if you agree with the founders' vision, leave if you don't"?
Too many cooks spoil the broth.