World Open 2013 10 way tie for 1st place

In the top open section there was a 10 way tie for first place. Their score  6 1/2 out of 9.

Each of the tied grandmasters received a prize of $3912.90.

What amazes me is that 8 of the 10 games were drawn.

My question is why did not the grandmasters who were scheduled to have the White pieces at least try to win?

If any of the 4 grandmasters who had White would have won that grandmaster would have received $20,000 and look at that against a loss where there was still some prize money.  Trying to win could have disconcerted his opponent. And at that level if the GM with White was not winning-then he could play for a draw?

[remember these grandmasters had already beat some very good players to get to the point where they had a chance to win the whole thing]

It seems math adverse not to play for a win?

In a related question and in such a situation I could see the two grandmasters getting together and one would agree to lose but [secretly] they would share the prize money?

I am guessing this might be illegal and certainly not ethical? 

[please correct me if I have any of the facts wrong]

Someone good in math please explain this to me.  It would seem to me on a math basis alone even if you have only 40% chance to win and 60% chance to lose "you should go for the gold"

Depends on what you mean by "go for the gold". Do you mean gold premium membership here on chess.com? (ponz111, you already are a gold member.)

No, I meant why did not one of those grandmasters who agreed to a draw try to win instead to take the very large first prize? [in that tournament]

A draw got them $3900  a loss maybe $1000  a win maybe $15000 or what ever the top prize was.

Therefore if say you thought you had 30% chance to win 30% chance to lose you have to go for first place don't you?

Even if you thought you had 25% chance to win and 35% chance to lose still the odds are go for first place and try to win. [someone tell me I am wrong?]

You could be unethical and make an agreement with your opponent that one of you would lose?

I believe you go for the win if the odds are anywhere close but the one exception being that one non GM might have to take the draw and lesser amount due strictly based on financial necessity.In other words, I am with you!

There were 8 players who did not go for the win and this still amazes me.

They could agree to split the prize money which gives them both incentive to win or lose but not draw. But I do not know if this is ethical or permitted?