> I do not have a problem with someone making a profit on those "gifts"
You seem to be assuming, though, that "not being a registered nonprofit" automatically implies that there's some non-trivial probability that you'll be profitable.
Every FOSS developer I've met who is accepting "tips" for their work, is not anywhere close to "breaking even" from those tips (insofar as you'd treat the FOSS project as its own business with its own balance sheet, rather than as a marque of the owner's hypothetical individual-proprietorship IT consultancy.)
Sure, some of these are side-projects they do in addition to a full-time job, and therefore the self-employment-wages they get paid out for this effort are "pure profit" in the sense that they already make a living wage. But that would be just as true if they worked full-time for a business, and then worked as a part-time paid employee of a nonprofit.
Profitability of a FOSS-project-as-corporation, is what's left over after you pay yourself (the sole employee) out at a working wage for all the labor you put in. As such, in legal terms, these side-projects almost always would qualify as non-profits.
FOSS developers aren't YouTubers with a fanbase of millions and a platform where they can directly, incessantly plug their Patreon to that captive audience with embedded advertising. They're just people publishing apps, where the app almost never event hints at the "personal brand" of the developer.
And so, I think a critical difficulty in the communication here, is that you might be imagining this thing on the wrong scale. We're talking about maybe 200 people per year, sending the developer maybe $5 apiece. Not about individual transfers of hundreds/thousands of dollars; nor about enough transfers to pay a living wage. That's why it makes sense to call these monetary transfers "tips", rather than "funding."
And that's also, partly, why people are so confused/appalled — Apple and Google do not serve their own bottom lines by getting in the way of people "donating" to these FOSS projects. The labor-cost required to enforce this directive probably costs more than they'd ever make by taking a cut of these tips!
> in exchange for actually going through that bureaucratic rigmarole to get registered
It's not the "rigmarole" (labor), it's the cost. A nonprofit corporation is still a corporation — and most FOSS developers, as individual proprietors, don't receive enough in tips to actually be able to afford the fees involved in incorporating and registering a nonprofit.
(I mean, they can probably afford it themselves. But the hypothetical nonprofit that is the FOSS project can't afford to pay for it out of its own treasury. I.e., incorporation would just put the FOSS project further "in the hole" in being revenue-negative, and therefore in being worth the developer's time to contribute to.)
There's a reason that governments allow individual proprietors to just "do business" without incorporating: it's a fiscal stumbling-block that trips up the people governments most want to encourage to start businesses.
The same thing should be true for nonprofits/charities, intuitively. Even if there is no legal recognition for "individual proprietorship nonprofits", everyone acts like those are a thing. (They don't expect their donations to be tax-deductible, but most people in the middle class don't donate to formal nonprofits enough to realize "donations" are their own, tax-deductible, class of thing, separate from regular monetary gifts.)
And most of all, people expects corporations to go along with it — and most corporations do go along with it. Microsoft with Github Sponsors, etc. That's why everyone is so up-in-arms that Apple and Google aren't going along with it.
Of course, Apple and Google are technically, legally in the right — these are not donations. The problem is that common sense disagrees with the law: by common sense, these should be donations, tax-deductibility and all. If push came to shove, the law — not common sense — would be what bends. But nobody's pushed that far yet.
> Side note - as I wrote before, my local tax office would like to know who the money is going to
Is there some problem I'm not seeing, tax-wise, with sending small monetary gifts to people you believe to be individuals who are online acquaintances of yours (e.g. people you talked to on a forum once)?
If I want to send money to a FOSS developer, it's because I view them as, effectively, an acquaintance. Someone I'd buy a beer at a conference. By "donating" to them, I'm just buying this acquaintance of mine a beer asynchronously.
Most people make small monetary transfers to individuals they aren't sure of the identity of all the time. For example, buying hand-made jewelry at a pop-up street bazaar. There's no "business" name — it's just an individual proprietor — and you might never learn the proprietor's name, either!
Because there are so many situations like this that can arise in every-day life, it's never the job of private citizens to prevent money from being unknowingly laundered into the hands of trade-embargoed states or entities. It's not your legal civic responsibility to avoid shopping at a store just because you haven't ruled it out as being a money-laundering operation.
Instead, it's the legal duty of banks and payment processors — with their fancy KYC/AML databases — to do that: to identify the transfer recipient through network-analysis at point of fan-in. Money launderers aren't fought by starving them of demand; they're fought by deplatforming them from the financial system they depend on.
(That being said, if you were acting as your own payment processor, ala https://en.wikipedia.org/wiki/Hawala, you might be on the hook at tax time.)