Bad vs good faith criticism. Most definitely let people dress how they want. No one can control that. And the opinion of one or a few people on the internet shouldn't hold bearing on how you express yourself as a person. Goth or not, that applies to everyone.
However, criticism towards modern trad goth isn't a personal attack on the person wearing it. It's not usually a go bully this person who posted a makeup look they thought looked cool. I don't use tiktok, but I usually hear more that it goes the other way around. Of oh, you can't be goth because goths are all white and pale with black hair. There's been pushback against this idea by people irl thankfully, but that it happened to begin with makes a statement about how closely online goth ties subculture to this specific style of makeup and all the shallow memes that come with it. Memes about graveyards and wearing black are fun and all but that and the neo trad goth style are all that some will ever come to associate goth with when it has so much more depth to it.
Going back to neo trad goth, it can't be denied that there's a lot of people who are just genuinely interested in it as a makeup style that don't claim to be a part of the scene. It has roots in drag makeup and I do think it has more validity in claiming equal roots from drag makeup and 80s goth. It's not just influenced by 80s goth, it has strong influences from drag. Neo trad goth says nothing about whether or not one is in the scene or not, just as how someone dresses also says nothing. No makeup, work clothing, but you could have been going to clubs for the past 20 years and there's no denying that person's in the subculture shpuld they wish to claim.
But here's an exaggeration, "I put on a style of makeup that's trendy and associated with goth and it makes me automatically goth by extension". What people online say is usually different, but the sentiment remains. People who aren't familiar with goth will think that the person with the white base and complicated eyeliner is more knowledgeable about the scene than an actual DJ.
Going back to, for me, it's not a personal attack against any one person who wears it to begin with. Rather, I do get mildly annoyed to see grifters peddling sponsorships and pushing goth as a mindset, but ultimately they exist online and I'll probably never see them IRL. I do also think it gets more popularity online than it deserves (and that's not the fault of any individual when we live with this algorithm favoring extreme looks).
I also have a personal thing of, I don't like it because I like how people's faces look. I think it can flatten people's features and make everyone aspire to a western european standard of alternative beauty of high cheekbones and thin noses. I don't think the makeup does that intentionally by those wearing it, but I don't think it cam be argued against that that is a genuine effect that it has. It makes me sad when people say that they only feel beautiful with it on because they have wide noses or darker skin that won't show as much contrast with black eyeliner. Like, there's a difference between using the white base for artistic purposes. Look at drag makeup. Versus doing it because you want to cover up certain features.
All this as a bit of rebuttal, as I don't think all criticism of neo trad goth is performative. But to add to that notion of touching grass hehe, some observations
In my local scene, that style is only really seen amongst younger people. But it's also common amongst general alternative people who are just into makeup. I see it more commonly at artsy events rather than at goth concerts. The older people who I know that do do some sort of lighter foundation don't really do contour + nose contour + heavily stylized eyeliner. Mostly eyeliner by itself.