I've got the feeling that you are partially basing this post on the notion that anybody in the history of this game and forum has ever turned around and said "These Sentinel Comics characters are like these real-life comic book characters" with the intent of marginalizing the insane amount of creativity, time and hard work that Christopher and Adam put into Sentinel Comics. I am pretty sure that has never happened here, and if it did, the forum would probably kindly and politely be down on the offender like a ton of bricks.
Sentinel Comics is inspired by other existing comic book universes - intentionally inspired, even. Looking for the occasions where homage has been paid strikes me as being totally normal behavior - for comic book nerds, anyway. Granted, some comparisons are pretty weak and solely based on shared powers and I really don't think the Hulk and Haka have anything in common at all. But I can tell you all of 5 ways in which The Wraith is like Batman: both have gadget-based powers, are super rich, have lost a loved one to crime, have inherited a huge company and live/work in a pretty rotten city. Doing stuff this way is a damn sight easier than saying 'Okay, this is a thread where we examine why The Wraith is NOT like Batman'. That would take forever and it's kind of a given, so we tend not to do that.
Anyway, it's not like we all have been lacking in praises for the insanely awesome, fairly diverse, multi- dimensional and fantastically characterized characters in Sentinel Comics. Pointing that out is like the number one past-time here on this forum - apart from making puns, maybe.
(In conclusion, I agree with you that the Sentinel Comics characters are not some low-res rip-off of other, more mainstream superhero comic characters. I also think the whole topic kinda is a nonissue.)