This sounds to me like a classic case of a fan having an image of who they want their idol to be with and the frustration and feeling like the idol is making a mistake that the fan feels when the idol chooses who they want for themselves.

I don’t know that in most situations, a 2 second questionable clip pulling a dog slightly hard, having a large Instagram following, and being admittedly vain qualifies deep seated disgust, name calling and hatred. Like, I get not liking the girl, but she like.... gets cats adopted and takes care of sick animals (which even if cynically is for attention, you could do worse, less value add things for attention). But most importantly, Howard is a pretty sharp, strong willed dude. Either he knows something about Beth that you don’t that makes him love her, in which case great. Or she’s vapid and an attention whore but he thinks how hot she is worth that to him personally, and then like - good for him. All power to you for just finding her annoying and not enjoying seeing content about her... you don’t really need a reason for that, you could just think she has a weird vibe - whatever.

But the intensity level of the hate here, and the ascribing moral value to traits youre guessing she has from what you see every now and then in a contextless social media, is just very extreme and seems kind of childish.