nidoking and queen are good examples of gendered designs because it's an interesting bipedal rhino beast and has somewhat believable dimorphism between the males and the females kind of like looking at a buck and a doe, or some birds where one gender has extra feathers or something.
Aside from the fact that I don't like the general design trend of the super anthromorphisized stuff that the franchise seems to be drifting towards overall (it's not like this "didn't exist" even in Gen1; magmar, electabuz, machop line, hitmons, jynx, mime etc... existed, but like post gen 5 basically every STARTER final form is some kind of furfag nonsense; it's like you see someone having a pet turtle or lizard or snake etc... but at some point it's like obviously just a person in a fursuit pretending to be an animal vs an actual animal, and if you're into that sexually then I guess that's good for you, but it ain't for me, so that's the end of my subjective criticism of this; I just don't like it.
But now onto the objective part, it just doesn't make sense as like a fuckin species. Why would all the males and females look so... strongly gendered one way or another? They should either be 'uniform' (e.g. m/f same sprite), have distinct male and female forms (I think nidoran line is one of the best examples of this being done well) or be mono-gendered; like miltank is only female. Also the 'conceptual' anthropomorphization is getting out of hand. Ok Magmar's a lava man who lives in volcanos or something, that's weird but ok I guess. Why the fuck does the litten species grow into WWE wrestlers? hawlucha is kind of more OK in that it's a standalone novelty, but honestly litten as a starter would be better if it turned into something more like a pyroar or a big tiger or jaguar or something that would look like a cool badass pet rather than your furry sex gimp. Honestly with the singular exception of Decidueye it's like every single starter in x/y and s/m turns into someone's furry fetish