I think some people will only fell satisfied in life when Sony alone detain all the market share for home consoles.

No, my friend. Publishers won´t abandone the XOne and if MS give them enougth money they will gladly build exclusives for the XOne.

It's the circle of life. We need franchises to die so that new ones can be created. If X1 wants to become this gen's Aokigahara so be it.

Depends of the game genre.

If it is multiplayer shooter like Titanfall,no because Xone is strong in USA specially with the COD crowd.

If it is a jRPG though.....

It really depends. Its not quite Gamecube/Xbox level suicide, where PS2 owned like 85% Marketshare. PS4 owns about 66% when speaking PS4 vs XBO. It can still be lucrative to make a game exclusive to XBO without entirely shitting the bed at this point. Now keep in mind the gap is growing and at such an early stage, you don't want to be left by the way side with such limited systems in the wild. MS makes up for any loss by offering boat loads of cash for Devs tho.

Why they pay for development and marketing for games they don't own? We don't even know what MS is paying for as they never stated,but I doubt it's enough to off set the loss that SE wil take missing out on their biggest fan base.How did that work out for CryTek?

Tell that to.DR, Ryse, Watch Dogs, MGS, Kinect Sports and Forza.

how should I do that ?

In Tomb Raider's case, I wouldn't say it's suicide, but it may do some damage to the franchises' image. It's generally not a good idea to piss off the majority of your fanbase (60-80% on PS & PC).

I would not call it suicide, since MS can probably put in enough money to make it worthwhile *cough* TOMBRAIDER *cough* but it will (obviously) mean much less exposure on 8th gen consoles.

Its not suicide but it will hurt the franchise a lot by being xbox exclusive.