Have to disagree with that, because yes people do. I'm one of them. If Pine is in it, 9 out of 10 I'll watch it, unless its a type of movie I just don't enjoy. I could care less about Hemsworth, however. I've never seen him in something that I've thought 'damn he can act' before, though I've probably thought 'damn he can't act' a time or two. I just think he's a pretty face, to some people.
I too watch some movies only because my fav actors and actresses are in it. I'm not disputing this aspect.
Point, rather, is about studios' perception of the general audience that, in large part, aren't fans of X actors to the extent others are.
My opinion is that we live in a time where big names don't sell as well as they used to in the old days. It helps to have popular actors, but not to the extent they'll make popular movies that the general audience isn't interested about. Cue Tom Cruise not being able to save the latest mummy reboot that was a flop (for his fault too, perhaps, if rumors about his ego and how he influenced the script are true)
In terms of this trek, I don't think I'll feel like watching the next movie if they recast one of the main characters.
So I'll just reiterate that keeping Kirk is far more important than bringing his dad back, no matter how much the actor may be popular thank to marvel.
Honestly, I'm even a bit bummed by discovery recasting Spock now, in spite of being another series and reality anyway. It's just that the torch was passed to this cast and they are the characters to me now, I'd love to see them being their faces for some time more before they give them new faces.
In the reboot, I also kind of have still some interest in it because of the cast. They made me love this version of the characters and I enjoy watching them play these roles more. Changing them, in a sequel especially, would pull me out of it emotionally. I said it before, but I'd rather settle for smaller roles than not seeing them at all or get them recasted.
This is an aspect the studio may need to take into consideration (the fact people love the characters as played by this cast) more than the mere idea that if you have X actor in your movie, it's going to be popular.
Even though, again, I do think that Chris Pine needs trek too. Maybe not as much as the studio needs him, but it's better for him to be in it than not IMO. Same for the others.
(This doesn't mean paramount should give them the short end of the stick and refuse to honor previously established deals)
Even $12 million isn't breaking the bank. Especially if the story hinges on Kirk.
I bet Marvel would love to be able to give Robert Downey jr 'only' 6 to 15 millions per film...
Paramount is so cheap.