There's really no reason for diode lasers to be 'under spec'. They aren't like dpss.
In theory, you are 100% correct. In reality I have three diode lasers from o-like which has a much better rep than DX, and they are somewhat underspec.
I think what he is saying is that there is no excuse with a diode. If they advertise 200mW and the driver only puts out enough current for 100mW then it is just a bold face lie. Vs green lasers where many more factors come into play.