The fact that plenty of people have gotten wage increases by threatening to leave their company disproves this notion. Your wage is not the point at which companies will let you go, it is the minimum amount needed to retain you.

"but to do it you have to introduce an unpleasant penny pinching theme into your relationship with coworkers and employer."

This is a sad sad culture where asking for what you're worth is considered 'unpleasant' to your relationships with colleagues and employers.