Abused, dropped... we are talking about a bunch of audiophiles and their DACs. While I'm sure there's some natural wear, but abuse? Drops? If something were dropped significantly enough, then it's likely the DAC wouldn't work at all. They're circuit boards, so unless they employ tubes in the DAC circuit, it's unlikely any kind of drop would affect performance on a measurable level, rather than outright killing it.
Wired incorrectly? If something is wired incorrectly it's because of the company and their QC, which should be treated exactly as it stands. Do you think testing all golden samples by companies would be better? I personally don't want to read about all tests done on pristine, pre-screened review samples. I want to know how their equipment, that they send out to actual people, measures. Regardless, some of the equipment here is still sourced from manufacturers, but I will say I trust the ones coming from members a bit more than those.
Otherwise, we're talking about DIY and mods, which can be evaluated on a case-by-case basis. Amir's going to find out pretty quick if something isn't performing the way it should, as he did with the Jotunheim and its absent case grounding.
He isn't some random reviewer.