I think it's a side effect of the "fad". There are so many people now who choose to eat "gluten-free" because they think it will make them lose weight or look cool or whatever it is that motivates them.
But back in the old days (1980's) when my Mom was diagnosed, she got the same reaction. I will NEVER forget that horrible woman at a potluck Mom and I attended who said to Mom, "What's the matter, our food isn't good enough for you?" When Mom tried to explain that she had celiac and that anything with wheat would make her really ill, the woman replied, "That's ridiculous!" I wanted to hit her. I mean I REALLY wanted to hit her.
I don't know what the answer is. I guess just keep in mind that there are people who are like that. No matter WHAT the issue is, some people will have a nasty attitude about it. Then come here and we will commiserate with you.