I literally disagree with everything you said.
First I don't agree a request should be made to unsubscribe. There shouldn't have been anything to unsubscribe from.
Second it's not the project owner's fault simply because their contact information is out and about. You're saying spamming people with promises of money that has their legal name attached to is just fine and it's the people's fault they allowed themselves to get spammed.
The worst thing, even, is that the people doing the donating have no idea if their money actually got to the person they intended it to.
> I also don't agree that a "project owner" should get to deny any potential contributors to receive donations based on his own personal objections.
This is the part I most strongly disagree with. You're trampling over people's livelihoods, principles and personal choices. Accepting donations has legal repercussions. Legal repercussions the top4commit owners wilfully disregard and have no intention of paying attention to. There are countries with laws that'd make the open source developer liable to damages and tax evasion.
That is only the legal part. The principle part is that many people don't write open source software to get paid from it. They have abdicated from gaining monetary advantage from distribution of knowledge. If you want to pay them, hire them and pay them for their expertise. It's a personal choice, one that is being disrespected here.
This project should simply work on consent-only or be dismantled. Remove all current repositories and advertise to gain project owners who actually want to be there. The people who created tip4commit have no legal expertise or intent to get legal advice, they're not helping the Open Source community, and most of all they have no transparency or accountability in the event of fraud.