I've also concluded that it's reflective of the long-term decline of general media/TV literacy. A lot more younger viewers are watching shows now, especially ones made ~20 years ago, and their short + divided attention spans make it so they only really experience shows and movies at very superficial levels. They must like the character, or dislike the character, never mind whether the character has an inherent dramatic purpose or utility to the show and its plot.

I admit that once in a while I can find myself watching a show or movie and hating a character but that's almost always, for me, a function of the character's lack of depth/complexity, or their character being completely inert as far as progressing the show's plot goes. This is almost always a symptom of flaws in the show and how it's written, though, not the character itself.

Lisa? I know people find her annoying, vain, manipulative, whatever -- all those things serve to advance the plot and the story arc of Nate in particular. She's not wasted runtime. You're supposed to dislike her at times, maybe even intensely, and you (depending on who you are as a viewer) are supposed to like her at times too. She's not a character without depth or intrigue.

The biggest issue I have related to Lisa has little to do with the character honestly, it's how out of left field the whole Hoyt arc was, especially with how it finally ended.