To elaborate on this point: if your current VCs aren't able to change your mind, and they get angry as a result, just their absence alone from future funding rounds will make it nearly impossible to get other investors interested. So they basically have you by a chain.
That's what the parent poster is getting at. In SV, most founding teams retain control after a seed financing, and many continue to retain control after a Series A.
Note: they're very good at the latter.