I agree. SO could eventually be a bigger franchise someday. It's a spiritual successor to ratchet and clank imo, and really could have much better sales on a console with a fanbase who actually like Ratchet and Clank. This could have been a much better seller. It's like ff13 between the 360 and ps3. Like, why would you put ff13 on a console that doesn't have a fanbase for that genre? All you really did was sell to multiple console owners and people who would have bought a ps3. On top of which, it was a mediocre game, which just acts as a bad first impression for new players.
I really hope they made money on it, and I believe SO should come to PS, if Insomniac has any say about it. Hell, they should re-release it for ps4 as soon as they possibly can.
EDIT: Looks like I responded more to the second part of your post than the first. Locking this game up should be a no-brainer, but the IP itself needs some work if Insomniac ever wants it to be a great seller. Because it doesn't have the traditional ps fanbase to turn to for easy sales, they have to make their game that much better quality if they want to improve.
I would say the game though is much more similar to Dead Rising on the 360, though. Initially exclusive, then a second entry port, then exclusive again, with much more similar sales than Gears.
Fun fact: I just typed in Dead Rising into the database search engine and the first result was "gears of war". Weird.