Why? Well.. that also depend upon brand preference isn't? Anyway system integrators offer various brands PSU and my friend's pc has corsair vs series for his entry-level build.. i will share his build
Go to jonnyguru or any reputed psu review site/forum & you will know why MWE is bad.In fact
@chimera201 already posted here a review from jonnyguru of master watt lite model & as per rule of thumb this can be taken as an indicator of overall quality of entire master watt series.
Power Supply Suggestion Thread 2017 Q1
Cooler Master Masterwatt Lite 600W 230V Review
P.S. Corsair VS series is even worse,I would rather delay my whole system building than taking chance with VS series for anything 1050Ti or above & a recent quad core processor.