Probably because they don't want to get called out when a site like this can't replicate they're results. That's a little bit of a harsh conclusion but you and me have talked before Peng about our skepticism about they're amplifiers really delivering they're ratings into lower ohm loads they spec.
On that one I have actually changed my mind slightly, after realizing they did claim the gen2 MCA amps (mine is gen0/1) used one power supply for all channels. My apology for jumping to conclusion too quickly... I don't like that approach (shared PS) but it does have the advantage that the one shared large power supply could push more current into 1 or even two channels, hence the 2 Ohm rating that otherwise would look fake. That even allowed them to use a lot less storage capacitance than the likes of the Halo A51, Monolith 200WX5,7 amps. I suspect the main reason they did it that way was more about cost, realizing they now have to compete with more high power class D amps such as the Hypex and Purifi based ones, and the Monolith amps that are becoming quite popular; and less about engineering merits but that's just my opinion/guess.