I don't know why they hate Lara so much, but hey, if it doesn't matter
As one of the "haters" I'll try to explain my POV, maybe you'll understand at least part of the position: the first minute of the game are a good recruitment ad for forces against her, lmao. If a woman I'm involved with exploded at me like that out of nowhere I'd be showing her the door. Or maybe ice-cold shower while she was dressed first, then the door. That was straight out domestic abuse, dude, unprovoked even. She was out of control, histrionic, hysterical and violent. I've been in an abusive relationship and since then the way a partner fights in a squabble or reacts is a good indicator of personality and Lara throws off all the red flags and alarm whistles for me.
She has serious anger management issues, plus there's the way she treated Erica and I could go on with reasons that make me dislike the character. I get it, there is kink for older MILFs, but for me quality of personality is the deciding point and she failed miserably on that test. If MC and she were real people I wouldn't see their relationship lasting more than another year or two before exploding messily. Mike is fucked already though, he'd be paying child support and palimony for the rest of his life, she is vicious enough to not want to remarry even if she found another guy, just to keep milking Mike.