How's this for unpopularity:
Having Nidoran
and Nidoran
as separate species is archaic and should be fixed. Ever since form differences became a common thing in Gen IV, the Nidoran-Nidoran split should have been merged. There is only one Wormadam, despite it having three vastly different formes depending on evolution. Only one Combee, despite the female evolving and the male not. Only one Shellos, one Gastrodon. One Wurmple. Male and Female Snorunt and Kirlia are the same species. The two forms of Unfezant are arguably as dissmiliar as Nidoking and Nidoqueen, the same goes for both Frillish and Jellicent.
Back in Gen I, it might have made sense to count the Nidoran forms separately. Gender wasn't a thing yet, and gender differences still several generations away. But in later generations, it has been a confusing mess, and led to some interesting mechanics clashes (such as Nidorina and Nidoqueen being unable to breed). Meanwhile, bred Nidorino and Nidoking can produce Nidoran
as an offspring.
Fixing this wouldn't be that hard either, although it would imply great changes to the Pokédex. Merging the Nidorans would shift all subsequent Pokédex numbers down by one. It could be remedied somewhat by moving Cleffa from #173 to #34, and Wynaut from #360 to #173. Chimecho and Absol (#358 and #359) could have their numbers go up by one, putting Chingling in at #358 before Chimecho, from its current placement at #433. Had this occurred in Gen VI, there would be no further problem. However, the evolutionary isolation of Gens V and VI make further shifts more impractical.
Instead, we're stuck with the annoying remnant of the limitations of the original Pokémon games. It was not fixed at earliest opportunity (Gen II). Not when it would have made thematic sense (Gen IV). It's too late now, and it seems we'll have to accept one Pokémon split across two dex entries, and sterile Nidorina/Nidoqueen for the foreseeable future.