It's a bit like "just do some exercise" for depression. It's not wrong in that if you achieve it it'll help, but it's also something that's common knowledge and a lot easier said than done in practice, so it's not useful advice and kind of irritating when you hear it over and over again.
Keto also helps (sometimes) with depression though: https://www.youtube.com/watch?v=q7jg6wlD6gY (The Truth About Treatment Resistant Depression: Part One (Breaking the Myth))
And it's not "just do some keto" in this case. You have to be very strict.
But there are many dosages of keto diet and you have to do it correctly.
Epilepsy keto is hard for real and takes commitment. You will never eat modern food again in your life. But better than life-long-suffering just to eat cake.
So, because it’s hard to lose weight, solutions that work (which are hard) get shunned and argued against?
This feels like a “the truth hurts” kind of thing. Or a “personal responsibility isn’t my problem!” thing.
Maybe that’s the whole point though, anything that requires personal responsibility and accountability is rebuked.
What's your definition of 'solution that works'? Because yes, running a calorie deficit is a solution that works (for losing weight, it may cause problems for other, perhaps more important, goals for some people), but telling someone 'run a calorie deficit' is not, in general, a solution that works if your goal is to help the person lose weight (it can actually do the opposite, in fact, if you're sufficiently obnoxious about it). It works fine if you want to just blame them for not losing weight, though.
So yes, at certain point a person is responsible for themselves, but on the other hand, if you have a goal of reducing obesity, you're not going to get anywhere by just saying 'well, everyone who's obese is responsible, and I am going to do nothing about it but remind them of it'.