> Wikipedia seems to do just fine without.

Because donations are a system that works very much in their favor and not at all in favor of other types of projects. Look at the OpenSSL Software Foundation having received less than $2k in yearly donations during the leadup to heartbleed.

> Commercializing a product is a whole other field, and it's not reasonable to expect everyone to be good at that, and not reasonable to expect developers to all take on a second job of commercializing their hobby projects.

I very much want to disagree with you, but I do not know how. Achieving some commercial success if you do look for it where others with your skill set are successful is not too difficult (see the trades), but the whole point of such projects is the exact opposite: Doing things differently and pushing accepted boundaries to where you think they should be.

On the other hand I think that this is acceptable. As I wrote in another comment, the obligations in these projects mostly arise from what the developers wants to commit themselves to (or, sadly, do so mistakenly). It is very reasonable to e.g. not value the long term success of your project highly.

You might want to just share an idea, maybe someone else will carry on your project or maybe if in 5 years someone shows a picture of you proudly presenting your project, you're like "AI has gotten really impressive, if I didn't know better, I don't think I could tell that this is a fake". And if you're anything like me, strong commitments to internet strangers might be life-threatening. 2 out of 3 times a promise I made got upvoted, I got hit by a car within less than 48 hours of making it and not once otherwise. An up-arrow got just one pointy end, a GitHub star 5. I'm not taking chances.