So rather than do anything productive I've been picking through my pre-Crisis Wonder Woman reprints for Steve heavy stories, trying to pinpoint exactly what made Steve so unlikable to other fans. I mean, my first exposure to the character was reruns of the television show, where he was this smiling (everyone on that show smiled a lot), sweet, optimistic man without a shred of malice or deceit. Maybe that had tinted my view of the old comics.
Thing is, I have yet to come across a particularly assholish piece of behavior. (And yes, this includes the famous dream sequence in #127 where he thinks of all the downsides to marrying a career superhero.) There's a storyline where they have a fight in the 70s because he just came from the dead and thinks she's babying him too much, and some sprinklings of the sort of sexism you see from EVERY male character in the Silver Age but ultimately, I still like him a lot. This is another one of those characters that makes me smile every time he is onpanel.
I will give you, there is one very weird story where he's about to go on a dangerous mission and won't see Wonder Woman before he leaves... so he asks Diana Prince to pretend to be her so he can make believe he had a last day with his girlfriend. It is the sort of crazy that comes about solely because they need a secret identity story, with him not giving her a chance to slip out of his sight during the story. I also think it came about because he's just not as smart as Lois Lane, so they couldn't do a "I will PROVE that you are really Wonder Woman" story. So instead, they have him completely oblivious to the secret identity. And rather than be suspicious of Diana Prince, he likes her as a friend and wants her to share his love of Wonder Woman with her. So he talks to her about his girlfriend, and insists she come with him to see Wonder Woman in a parade, stay to meet her and other things until we get to this level of weirdness.
In general, I like Steve a lot more than the other male characters embroiled in Secret Identity soaps, probably because he's not the one playing the game. He doesn't have an inkling there's a game going on. So while we see Superman and Lois Lane caught in this web of mind games and paranoia and deceit, Wonder Woman is trying to handle a completely honest and enthusiastic person. Even when they take him over the edge to contrive some situation where she can't hide, they don't have it be suspicion or manipulation like with Lois. He is dragging his best friend along while he takes care of his problems. Poor Diana can't curb his pushiness without betraying her true self so she plays the part of his beleaguered army buddy that he's dragged to the park to see a show.
I think this is one thing that really worked, though. The story of the Amazons has Hercules deceiving them as their greatest shame. Ares, a deity not known in mythology for mind games, is often cast as a "Prince of Lies" style enemy who tricks men into warring against each other. She has villains in Dr. Psycho and the Duke of Deception. These things are still there post-Crisis, with the added pressure of Diana being a living lie-detector that wields the lasso of truth.
Deceit is a bad thing in this franchise, and an especially bad trait for a male character in this franchise. Diana's grown up being told that evil is spread through lies and that the greatest violence of men is preceded by lies. The ultimate expression of wickedness in men to her is lying. Any male love interest of Wonder Woman must be an honest man. Pre-Crisis, she had the most honest man in comics.
This level of openness added to his endearing naivete, which in turn added to his charm to a protector/nuturer like Diana.
Post-Crisis... well... Her most recent male love interest was Nemesis, the master of disguise. This was interesting, pairing the embodiment of truth up with a guy who's heroism is based on deception, and I enjoyed it but it didn't work for too long.
What worries me, though, is this is another thing they missed in the animated movie. Steve's mostly straightforward in that, but there's that fucking bar scene. He's your horrible stereotype of a deceitful man who only seeks sexual conquest in that scene, and that takes away what makes Steve a special enough man for Wonder Woman. All so that we can have her angry at him and saying her mother was right to warn her about men... and then have her turn around a couple scenes later and forget just how fucked up what he tried to do was.
God, I hate that bar scene.