In fairness, that letter written by Sawyer is framed in a very biased and inaccurate manner. For example, he statement " Which set of changes do you think I heard more feedback about? If you guessed the marginal drop in proc rate on the soulbound item that had only worked properly for two weeks, you’d be right." is...intellectually dishonest. The dagger in question had it's proc rate dropped from 10% to 3%; that's not "marginal", that's 2/3rds of it's bonus proc percentage. But acknowledging that doesn't hep the narrative Sawyer is trying to frame, so he implies that it's a smaller change than it actually is. The whole thing is full of stuff like that; it's not an honest discussion of why Sawyer believes these things so much as it is a justification for his view of game systems.
I have to disagree, and you prove Josh's point about feeling losses more than gains nicely in a way.
In cognitive psychology there's a concept called loss aversion that fits this behavior in a fairly nice way.