1) Who cares?
2) One perspective is that he was generous about sharing his opinion with HN. You, however, are accusing him of writing a DISHONEST REVIEW with the SOLE intention of MANIPULATING the reader into making a purchase.
3) Everyone is always selling something, you're selling a reputation of being the noble crusader of HN.
Incidentally..
1) For those who aren't as materially wealthy as you, a few dollars from an affiliate commission can be meaningful.
2) Aff link stats can be a useful metric of influence
