I'll disagree on the male nail polish not being necessary. While yes, the formula is the same, there is value in having male marketed items, and not just for the first timers.
Male-marketed items not only make things more acceptable for newbies, significant others, and such, it generally also moves them to more male friendly spaces. Guys don't want to go spend a bunch of time in a hyper-feminine space, which is what nail salons and the cosmetic section at the store where the polish is kept tend to become.
Some of the names of colors I've seen are cute plays on words, many with sexual connotations, which are in no ways gender neutral. Male marketing doing the opposite it healthy and to be expected.
And while you may sneer at drab, limited color choices, if one is looking for colors that work with your male wardrobe, those colors can actually be hard to find. The pinks, purples, and pastels are plentiful, but trying to find the right shade of blue or green, brown or gray, can be a challenge. Not impossible, but still, I'd take some help from a company that had a good array of guy options.
Having male marketed options also helps indicate to the wider population that it's okay for men to wear/use these things. Whether their existence is a driver of changing attitudes or an indication of how far we've come, it's positive. I think it's some of both, and when I see such things, I take them as wins.