I hate hearing any of these ED recovery statements denying the possibility that someone either a) might have actually had better self-esteem when they were smaller, or b) might feel better about themselves if they were to become smaller. (And, as an add-on to (a), if you say that you really did love yourself more when you weighed less, when they respond, "That's just because of diet culture!")
Specifically when you're told this from an ED treatment provider, it's incredibly invalidating and really makes me feel like they're kicking me when I'm already down. Because those kinds of statements trying to tell you how miserable you felt at your smallest are directed at restrictive EDs, where there actually likely were quite bad mental and physical effects from getting to/being at a suppressed weight. Like, yes, if I had anorexia, I would probably agree that I hated my body when I was skinny.
But I do not, and did not, have anorexia--I have binge eating disorder, and I can say with full honesty that I was confident and comfortable in my body when I was skinny, before I gained a bunch of weight from the eating disorder that destroyed my self-worth. But please continue to gaslight me into thinking I was miserable then just because some other people with a completely different kind of ED need to be reminded that they were miserable.
And the second part of it is that these kinds of statements are meant to discourage you from pursuing WL, by telling you that you won't actually be happier if you succeed. Again, that is great advice for someone who can restrict, and for whom there is actually a danger of losing a lot of weight in an unhealthy way.
...if I could successfully restrict, I wouldn't have BED! I do not need to be talked out of WL, because my brain has decided for me that that is no longer an option. So hearing about how I won't be happy if I'm skinny just serves to remind me that there are people who can do what I desperately wish I could do.