Why do people not seem to know what not guilt by reason of insanity means?

I’ve been watching the Lindsay Clancy case, and so many times I see people acting like not guilt by reason of insanity means she wouldn’t be punished or that means she didn‘t do it.

Psychiatric commitment is not fun, it’s not like she would be walking free. It’s awful there, you have less freedom than general population in prison if anything. If she ever gets out, which is rare, but possible, she would still have a very controlled and probably miserable life.

Not guilty and not guilty by reason of insanity are not the same thing, yet people are acting like they are.