You are now listening to somebody with a conflict of interest. Did he recommend X because it's great? Or because it pays the best?
The worst problem is that incentives distort belief. Watch friends who sign up for some network marketing thing. They find ways to be excited about their products. Basically, they end up liking the stuff they're pushing more, because otherwise the cognitive dissonance is too painful.
I thought about this conflict of interest too. But imo people should still be able to use aff links. Their trustworthiness should be deduced from other factors.
You're welcome to deduce trustworthiness from anything you like. But people have been asking "Cui bono?" for 2000 years, so you're unlikely to change many minds there.
When I worked as a consultant, I never took vendor kickbacks like these. At the very best, they created the appearance that I was working for somebody other than my clients, so that I'd have to work a lot harder to maintain client trust. The worst case was that they'd distort my thinking without me noticing, meaning that my clients shouldn't trust me.
I think it's the same deal for writers. The whole point of incentive systems is to distort behavior. It's not unreasonable that people assume that they work.
The worst problem is that incentives distort belief. Watch friends who sign up for some network marketing thing. They find ways to be excited about their products. Basically, they end up liking the stuff they're pushing more, because otherwise the cognitive dissonance is too painful.