For the record I 100% believe neither fat-shaming or skinny-shaming should ever be OK.
However, growing up in the 90s and having size zero shoved down my throat, being told I was fat when I was a perfectly normal size and just generally being made to feel like some worthless, disgusting subhuman has made me very defensive.
For decades it has been socially acceptable to abuse someone for not being thin. It’s only recently people have finally begun to acknowledge this is a shitty, shallow thing to do and not being thin doesn’t suddenly make you less of a human, even so, overweight people continue to be abused under the guise of “well I just want you to be HeAlThY!”
In a way, I think this has been what may have contributed to the uptick in skinny-shaming. Some people (myself included) have spent near enough their whole lives being told they’re worthless and to finally be able to push back against that and have other people support you is fantastic. Unfortunately as is often the case people are going about it the wrong way and trying to drag others down by making them feel awful.