Who ever wrote that review sounds like a dumba$$.
Because you are right?
Because he relies on results of 12 people using the operating system. 12 is too small a number for an OS and they were all the same type of user. No other information about the users were given, only that they were "experienced users". For about half his points he relied on just the observations of the users.
Sounds like he picked a bunch of his colleagues watched them use it for 2 minutes then wrote a whole bunch of information based on their incompetence, though that's just mere speculation.