thats sexist

wouldn't say that devs do it on purpose but rather "according to the statistics, most of ts4 players are females playing female sims so instead of making content for a kind of sim that isn't so popular, we're going to use the budget somewhere else".. especially cuz both male & female sims can use the same hairstyles & clothes (although these look a bit weird when switched and some clothes should be more unisex)
but i agree male sims could get more items & more variety. also a lot of people complains that toddlers & kids barely get any content, we can apply the same again, "young adult females playing young adult female sims" and the clothing can be reused for teens, adults & elders.