The nature of competition level are entirely different. Just because some fighters have shallower competition and therefore more impressive finishes, VS fighters who have tougher competition and therefore less impressive finishes at times, doesn't mean the performance of the former are better than the latter.
Sport should be a meritocracy, and in this case it seems they're going for flash over substance.
- A level athlete beats another A/B level athlete? No bueno.
- B level athlete beats another C/D level athlete? Performance of the Night!!
Hence, the fairest option is for mens fighters to be compared with other mens, and for womens fighters to be compared with other womens because that's their benchmark. Of course, some people here will now claim I want to invade Poland.