First of all, L&P wrote at some point that Sam is honest with Sophia. So even if it looks like that, there is no conspiracy!
Sam is completely exaggerated in terms of his abilities and appearance and Sophia is, although it hasn't been explicitly said, totally in love with Sam. This is the only way to explain her intoxicated behavior when she is near him. This is the only way to explain why Sophia simply overlooks Sam's misbehavior, his narcissism. (Perhaps also because Sophia also has narcissistic traits.)
For me, the reason also why Sam is seen and discussed so controversially is that his route is closest to an NTR or Mom-NTR route in terms of content (please don't turn this into an NTR debate, there are enough of those in other threads!!!!!!!!!)
I gave up on the Sam route at the end of the very erotic episode when Sophia visited Sam in his room. At the end, when his sister tried to enter his room, Sam of course refused her and finally commented on her behavior with the words "I don't know what's wrong with her today, she's probably on her period." It wasn't Sam's derogatory comment that bothered me so much, but the fact that L&P didn't let Sophia react to it in any way. That was the end of the road for me.
But that's a personal decision and interpretation of his behavior and that of Sophia.
Together with L&P's statement, you can instead say that it's normal teenage behavior from Sam and he's just trying to impress Sophia with his abilities and his "coolness".