Unless you have evidence to the contrary, then thinking all home cooked food is unhygienic compared to outside sources is odd, which you have pretty much validated, by explaining you have issues with food.
I've never said I think all home-cooked food is unhygienic.
What you eat is your own business, but if you are talking about insults and being rude. I think its quite rude to put perfectly good food in the bin, implying or stating that home cooked food is dirty, disgusting and germ ridden.
Of course the obvious thing is to not accept it in the first place, but what are the other options once you've already been gifted the food, though? For example, if someone has given you some homemade fudge but it was wrapped up and you didn't open it for a few weeks as you were waiting for Christmas. Nobody has actually given me an answer as what the alternatives are if you're not going to eat it yourself.
You can't return it, you can't really re-gift it to someone else, you can't donate it to a food bank or charity as they won't accept it, so if you won't eat it, what else is there to do with it?
I don't bake, but would imagine a few home bakers might be quite offended by that, what about their feelings?
Well, if I was a home baker, I wouldn't bake for people who hadn't already asked me to do so, so no feelings would be hurt if they said no.