The dynamic changes as soon as founders give up control of the board. It goes from investors having to convince founders of major decisions to founders having to convince investors. It also makes the founders fireable. The founders become effectively employees of the investors. This results in them becoming become averse to "rocking the boat". It's a very powerful negative incentive.
Investors have more than enough control over a company using money, minority board seats, and the potential of follow-on funding. Founders should control the board as long as as they're running the company.
A famous example of how bad boards can be is Facebook's board wanting to sell to Yahoo for $1 billion. Zuckerberg controlled the board and vetoed the idea outright against them. Facebook is only worth $600+ billion today because he maintained control.
