Why do developers make an "Exclusive only for ____" game? Won't it be easier to market their games if they were made for all the consoles and the PC?
Let's exempt Strategy for this one.
example: Microsoft owns rights to halo.
So if you wannna play Halo, you have to buy a Xbox 360.
Therefore: More profit.
Usually Movie Tie-Ins "just plain suck", but that doesn't stop children from liking them, except in that case children never know any better by default.
Exclusives are merely a way for a developer/publisher/Console company to make more money on certain titles.
Like when Microsoft releases 360 exclusives for Windows PC. It's still Microsoft exclusive, but that opens it up for PS3+PC owners to play it, increasing their overall sales of a particular title.
Sometimes exclusivity to one console makes an incentive to buy said console when you otherwise wouldn't, meaning more money. Otherwise, wide market saturation would result in similar or better profits if there were no exclusives.
Console'rs may love Halo, but that's only because they quite literally don't know any better. When it was ported to Windows, it ended up being sub-par at best, and that was because the game turned out to be a re-hash of older PC games. Everything about it has either been done before or was done better.
The Repetitive Levels complaint being the most prominent and most unforgivable, and rideable vehicles were done several years before the first Halo game.