and who will till the soil, weed, fight pests, harvest, etc.

In the case of a home garden, the homeowners, just like it's expected for a homeowner to care for all the other plants on their property.

In the case of an allotment/community garden, community members would provide the labor. That's how they currently work.

I mean I get it. I'm a rich white person with a lot of leisure time and I own property where I can have a garden... but turns out not everyone has this stuff.

I'm confused what the problem is - just because you know some people that wouldn't benefit from a home garden subsidy, doesn't make it a bad idea, if it encourages more people to grow food at home. It's not a one-size-fits-all solution to be sure, but it is a solution that would work for some, with little to no downside that I can conceive of.

Also the whole "you need a lot of land if you want to garden" thing is kind of a myth. You can do a surprising amount in containers, with vertical systems, or even indoors with grow lights or hydroponics these days.

Edit to address your edit:

Gardening is great. But jerking myself off and generalizing and saying everyone else should be doing what i have the luxury to do... just makes me a smug self-righteous ass. People buy food from stores because it's convenient and fast.

I don't think anyone's saying "everyone should garden", just "more people should garden". The original suggestion we're discussing was to subsidize gardening, which would help reduce the barrier to entry and make it a more attractive option. Option being the keyword there - subsidizing something doesn't mean everyone has to do it, and it certainly isn't an attempt to belittle or shame anyone that can't or doesn't want to garden.