The world is intentionally un-realisitc. It's a comic book world. Would any person ever live in Gotham City? No, of course not, it's where every super villain congregates. Normal people would move.
Rockstar gets a pass for it's poor storytelling, awful pacing and diametrically opposed game world v. story world (I'm so conflicted about murder despite murdering thousands in that past ten minutes!) or mechanics being inconsistent with the story so they are dropped sometimes (RDR's dead eye) because it makes an effort to be grandiose. Game writers eat that shit up generally speaking. If you make an effort to tell a "good" story (even if that story is just something you've seen a dozen times on Law and Order or other cop serials...Heavy Rain) game writers tend to reward you if you pulled it off or not.
I think inFamous is more fun most definitely but also a flat better game because it accomplishes everything it sets out to do. It makes you feel like a super hero and lets you play through a ludicrous comic book story in a ludicrous comic book world. At no time is the story world broken so that you can play with your mechanics. When I injure civilians, I go heal them. If I don't, they die. If I kill enough of em, they boo me. In GTA 4 I'll murder people by the thousands but then feel bad when a gang banger kills himself because he is lonely. Give me a break.