I don't think he is angry, I just think he isn't comfortable having his projects listed on sites like this. Read his comments on the bug; they are polite, they explain his perspective, they ask for a specific action, they don't contain insults.
In your scenario, if you actually wanted to tip a meaningful amount, I think it wouldn't be a big deal to simply contact the project directly and see how they wanted to handle it. If you are talking about software users keeping $0.50 tips instead of the projects collecting them, I think that argument is sort of neutral to the opt-in/opt-out question (if a project thinks the combined small tips are worth dealing with, they will likely opt in).