Someone started dobbing in people to the teacher for being rude, so I'd like to point out that suggesting something is wrong or suspicious because someone likes a DAC from a particular maker or doesn't like a positively reviewed one is just plain rude.
I'm going to comment on DACs instead. I've had a couple of DACs here and tried many in-store (including SACD players that doubled as DACs) that have been positively reviewed and I thought they were rubbish. My theory is that:
1. Hi-fi magazines have such low expectations of what DACs will do (compared to vinyl) that they accept mediocre sound from them.
2. Many of the reviewers haven't ever experienced an old R2R DAC and how much better they sound, especially given many of them were very over-built, something you only get now in insanely expensive models or from obscure companies like Audio-gd.
3. They are always being reviewed connected to expensive power conditioners that negate any faults in the PSU design and the DAC ends up sounding good.
or some combination of the above. The rubbish-sounding DACs most definitely improved between being plugged directly into the wall (or a computer in the case of, say, a $1700 USB-powered DAC) and being plugged into a Power Plant Premier (or using a better PSU for the USB-powered one).
Other than that, personal preference and synergy with one's system I'd consider important too.