Philanthropy is great when it's done by independently wealthy people. If that's who the author of this project is, then that's great and I've misjudged this. But that's not usually the case. The majority of mildly useful little unmonetized projects are not made by independently wealthy folks, they are made by (usually younger) folks who are optimistic and whose expenses and responsibilities have not yet accumulated. I don't mean to be a debbie downer - fun little projects are great - I'm just saying that I don't associate something unmonetized with "great! this is altruistic!", I associate it with "bummer, this will probably not be sustained", and when I come across something with a natural and well-aligned monetization scheme, I feel positively about it and am more likely to use it.

I'm honestly curious how you envision that affiliate links might create the wrong incentives. There are other ways to make money, but the ones I can think of seem much worse. Advertising sucks and clearly has more wrong incentive problems. Donations are less predictable and disconnected from the usefulness of the site. It seems to me that getting a small cut of "hey this book does look useful, I think I'll buy it!" is as well-aligned as it gets. But I'm interested in your thoughts on this!

This

As a general rule, I steer away from review sites, and instead I look for professionals using the product. For example I follow some photographers, carpenters, etc, and see what equipment they use for themselves and why they use it. They are not reviewing products, they are using them and posting a list of products for my convenience.

If I decide to buy the same equipment, I see nothing wrong using their affiliate links.