Nah, He does raise good points. Let's face it, Liz only showed interest in the mc, after he became superhuman. It's insulting.
Why is it insulting to someone to only show interest when they become someone worth being interested in?
Let's face it, MC before he gets his powers is nothing. He's unmotivated to do anything, he's short, he's ugly, he's weak, and there's no real positive features that stand out aside from his tenacity (shown with Deryl during their feud), although that could be construed negatively as stubbornness.
MC after he gets his powers is confident, decisive, motivated, tall, hunky, strong, etc. Some of those traits are superficial, but some aren't.
Also, it's explicit that the reason she turned down the MC the first time he asked is
because he's unmotivated.
Liz is a willing slut who more than likely has a body count in the hundreds (nothing wrong with that, it just shows she is not girlfriend material), Amber is a hypocrite.
I would argue the past only matters to inform the present. Liz isn't a "willing slut" because she loves having sex so much she can't control herself, she just feels empty. It's made clear that she's only going to have sex with the MC if they get together, because she no longer feels empty.