There are U2 fans (like myself) who like Bon Jovi - which is like fastfood - you get the same thing and the same product all the time and is nowhere near gourmet but you still enjoy it.
Others like "derivative-disguised-as-artsy-and-original" Radiohead.
A lot of American U2 fans are big fans of Bruce "nothing-significant-since-Born-In-The-USA" Springsteen more because of what he stands for and how they relate to his lyrics which are just rehashes of previous themes.
Then some here are fascinated by "economy" or "low budget" versions of U2 like The Killers (I love them), or Coldplay (I can't stand them), or Muse.
The older ones in this board love The Rolling Stones although they don't know any song or album they did after Satisfaction.
With a band as great as U2 and for all of us being music fans, it is only natural to like other bands even though they are inferior to U2. Nothing wrong with that.
But with Maroon 5, I cannot imagine a "true" U2 fan actually liking there music. Maroon 5's music simply has no social or artistic redeeming value to even make it have any worth to real U2 or music fans in general.
Of course, this is all just my opinion and your mileage may vary.