Jason (DwE) was a total blank slate. We only knew he has a college degree and an awful job way below his education. We could choose if we wanted to be 'romantic' or 'sexual', and we could succeed either way as long as we were consistent. People complained about him being bland and an underdeveloped character - he was basically a loser with no defined attributes other than being 'nice'.
Marc (RfJ) has a good job, seems like a nice guy and only needs to be 'complex' (that is, not answering always in the same tone) and not a horny dog to get Jessica. He is bigus dickus too. Some people complained about him being too nice that is almost unrealistic that a rockstar would even look at him, others about the game being too difficult because they had to balance their answers instead of going with a monotone behavior. And almost everyone complained about him being, again, an underdeveloped and bland character who didn't exist beyond his job and his infatuation with the rocker chick.
Lucas (FM) was a complex character. He had a past, he was hurt (you could choose why), he had reacted in a certain way to that sad event (you could choose how). He was handsome, intelligent, had a nice house, a good job, a great friend. Had other manly hobbies too, such as motocross, and even played ice hockey during his youth. He couldn't even fail with Miranda, at most you'd miss the sex scenes but you could get the happy ending. So players could enjoy the whole story (bar the sex parts) even if they were stupid enough to not get a single option right. The gameplay, I'll admit, was a bit clunky due to some answers being too similar, but in the end all you had to do was to be consistent with the 2 character traits you had chosen for him at the start. Of course, people complained: it was too difficult to feel immersed when you have to keep an eye for those 2 variables and your MC can be totally different from one playthrough to another.
Paul (SC) had it easier: no more scorechecks, just a couple of right choices and the girl you want is yours. He is nice, although we know he has destroyed too many relationships due to him being unable to move on from his high school crush - the canonical Paul is such a depicable person in his relationships that even his best friend decides to not confess her love for him because he would never be able to correspond and will leave her at jump if Chloe ever shows up again, even if that's highly unlikely. But nobody cares about those poor girls, we all should feel sorry for him because... well, we are him. He's broken due to that traumatic and forced separation, but in SC not only he can solve his issues with Chloe, but one day he simply can choose unregrettably if he actually prefers Xara or her long-time friend and secret-lover Serena better (heck, he can even get in a poly relationship if he play his cards right, and even bang Miranda on another route). Of course, leaving Chloe alone in her misery to look for an easy way out with Serena is not being a jerk despite that decade spent pinning for her, it's 'player agency'. No wonder people liked the game - until the canon route starts to settle in Chasing Beth, it seems. And anyway, the multipaths were short, so meh.
Joel (CB)... well, I'll just defer to what Mortze said above.
All of them are nice guys. In their canon route, all of them are supportive, intelligent, empathic, caring friends and loving partners. They love their girls, they stayed, and that's why they succeded. They all help their respective girls to achieve their goals, both in the Elsaverse plot and in their daily lives (Elsa gained confidence and trust in men, Jessica step out of her self-destructive spiral; Miranda got a helping hand to drive her away of her potential madness -at least momentarily, and Chloe could finally break off the chains with her abusive father and installing herself as the nice woman she wished to be). All thanks to these guys. They are the strength and the support those girls needed. But yeah, they are all a bunch of betas and Joel is the worst of them all because that bitch Serena is still undecided - despite what she actually says in game.