That's all just nonsense. Some shooter franchises factually more linear than C2:
Killzone
Gears of War
Battlefield (lol, not even close here)
COD (ditto)
Uncharted (if this is a shooter)
It is LESS open than C1, but still more open than most other shooters. You felt like you had more room in KZ2? What part? Can you link any youtube showing this space where you had "more room" in KZ2? Thanks. I just got through with KZ3 and the games are basically corridors. Which is the same with COD and BF of course. C1 gives you open sections. Halo, I didn't list it as more open than Halo because I'm unsure. It probably is though. Like this guy I cant remember most of the games I've completed that well section for section
http://www.neogaf.com/forum/showthread.php?t=471480
I'm just not sure what you're speaking of but if you're equating KZ2 and C2 linearity, you either havent played them or, well really I dont know any other explanation.
This knocking C2 for linearity when it is far LESS linear than the vast majority of todays FPS and that's a FACT is just disingenuous. But people want to keep on their blind C2 hate cause Crytek "spurned" PC's so they do it anyway. If you want a more open world PC shooter play Stalker 2...oh wait that dev went out of business because PC gamers pirated rather than bought.
I didn't play Dead Island, so I dont know, but if you're asking for FPS GTA, well I just dont think any of those exist, so it's not exactly fair to hold C2 to some mythical standard that doesn't exist for the most part, or if it does is a relatively small and unpopular niche (while linear shooters dominate the market). If you want an open world game, buy GTA4 or Just Cause.