Homemade cakes and biscuits don't 'give me the heebie-jeebies' and I eat plenty of them, just generally ones that have been made by people I know, and who at least appear to be normal, vaguely clean human beings.
I'm actually not especially hygiene-conscious. I couldn't give a flying fuck about touching door-handles etc and have been told many times (on Mumsnet, in fact) that I'm 'grim' and 'rank' for being more than happy to shag someone who hasn't showered for two days. I'll happily eat stuff from my own fridge that's out of date and
However, I've had a couple of jobs in which I regularly had to go into strangers' homes, and believe me, there are plenty of people, and homes, which are so utterly disgusting that I probably wouldn't want to accept a glass of water from them, let alone a homemade cake or a jar of jam. I've seen someone making themselves a sandwich on a worktop that had half a dozen dirty nappies piled up on it, and I've also seen someone scrape flies' eggs off a slice of pork pie with their knife before eating it. So I'd rather buy cakes from an actual bakery than a box at the end of someone's drive.
Fruit and veg or whatever is totally different of course; you're going to wash them and/or peel those anyway.
If people want to buy cakes that way, that's absolutely fine - people can do what they like, of course. I wouldn't fancy it myself, though, and I doubt the cake shed industry will collapse without my patronage.