GeniesLoki

Are "you're not bad for having this problem" and "you should improve this problem" fundamentally incompatible??

Hmm. I don't think so? It depends a lot on what sort of "should" it is, but I think it's actually entirely normal to have both of these be true. e.g. there are things you are obligated to be good at, but you have to be bad at them first, and this is not a moral failing.

for a concrete example, think of a fat person. is accepting them for being fat at odds with motivating them to not be fat?

I think this is a good example of it depending on what "should" means. I think the correct position here is roughly "Here are the benefits you would experience from not being fat. I will support your change if you decide that's worth it, and accept your decision if you don't."