I've honestly come to the same conclusion, that a lot of people just have no clue how to react because they've never encountered a stutter before and some of them blurt out the first thing that comes to mind. It's actually one of the reasons I disclose a lot these days; the way I view it, I'm actually doing these people a favour in terms of telling them "hey, THIS is what's going on here and THIS is how you need to react to it". I often get incredibly positive reactions following that, and tbh I wonder if part of it isn't exactly that - that on some level people are grateful to me that I didn't leave them to blunder not knowing what to do. This theory was also borne out by the fact that the last time someone did the "ha ha did you forget your own name?" thing to me, I just looked at him blankly and said I had a speech disorder and this dude just sort of... *dissolved in shame* in front of me? Full-on grovelling as he fell over himself apologising? It was a real shock at the time because I figured people who said that sort of thing were intentionally being assholes (like. what do you *think* is happening when I struggle to say my own name, friend) - it made me realise that some may just be being total idiots instead.