Just curious would this ever persuade someone into buying a game?

No, not really.

I did buy Stranglehold because of Yun-Fat, actually.

No.

What would be the point in doing so?

I also dont buy a game just because a specific developer made it. I always check if the game is worth it before buying it.

I also dont have a favorite musician because I like individual tracks not musicians.

Hmm I have never before, and I don't think it would compel me to buy a game no matter what.
It would probably help if it was the type of game that looked kind of interesting and you were on the fence about buying though.

No. I like William Dafoe but I wont buy Beyond Two Souls.

No.

Besides, i dont have favorite actors and actresses. There are some i like, sure. But, when you start following them, you realise they are bringing their personality to each character. For example Tom cruise seems to always play the same character regardless of the movie. I try to enjoy the movies by themselves to prevent annoiyances of that kind. If i notice the actor is doing that, i can no longer enjoy the movie the same way.

Nope.. That would be a bit silly if you ask me!

I have if you consider the WCW/WWE games

So why are developers wasting their money by hiring expensive famous actors.