No, it's criticizing him for not being forthright about it. I think it's important for people to know whether or not their activity is helping financially support someone. I may specifically want to support the project maintainer, so I will try to remember to use their referral link later if I don't have the time to do it now. Or I may specifically not want to support the maintainer, so I will circumvent their referral link. Either way, my job is made a lot easier if the maintainer discloses that the link is a referral link.