If you're a random worker of a huge organization and it gets bought or co-opted, yes you should jog on. Go help someone else that hasn't been co-opted.

This is why even though I'm generally a progressive I'm against unions. The solution to bad owners is everyone quitting their company. This was not feasible in a town with a single factory but is very feasible today. Quit working for bad people and bad people will change or become powerless. Prolong the ability for them to keep workers and they will keep being exactly as they are.