And how would what you're doing differ from "diagnosing someone based off a blog post"? You've decided they don't have it. Do you have information other than the blog post that allowed you to come to that conclusion?

"By the way, don’t tell someone who is disabled and was hospitalized several times with a mood disorder that they’re gatekeeping a disorder."

Why not?

I'm not saying it's what you're doing here, but it's quite common for sufferers of a particular condition to gatekeep their labels and online communities.

I do it myself!

Typical example: "Everyone is a little bit ADHD." Um, sure... but I can 99% guarantee it is being said in bad faith to discredit actual suffering. GTFO!