Let me help break this down a bit.
There are very good reasons, most objective, to why I don't consider laziness or incompetence to be an adequate excuse in art. At least not when charging money for a service, said artist is unable to provide.
1: Imagine you are paying for an art piece. Say you are promised 10 hours of work.
You get 6. Because "Well, you asked for a female." whereas the guy that asked for a male gets 14.
You both paid the exact same amount.
2: Now, imagine in the price, you are promised "any species, any gender". You have free reign to pick ANYTHING you want. Except: If you ask for female. That's it. Choices over. You're getting a prepubescent human, end of discussion.
But as said: If you ask for a male. You can pick whatever the fuck you want. Even a double rainbow sparkledog dick.
3: If you have any objections to this, you are berated by everyone for being "picky" and a "whiner". Simply for remotely wanting the service you PAID for. Imagine doing this in ANY other profession.
Or better yet: IN this profession. We all know that if someone refused to draw specific penises and short-changed anyone that got a male from them, they'd be fucking found dead within a week.
4: So in short: People that cannot provide a proper, matching pussy are: Failing to deliver on a service they are charging for. REFUSING to learn how to do it correctly. All while bragging how good at it they are.
To be clear: People that offer a discount on the females are okay in my book. As: They charge accordingly. If someone is incapable of doing something to an acceptable level: Knock it off. No-one (sensible) would pay for a service someone can't handle, just because they are good at another service.
5: They are providing an objectively worse service. There's no way around this.
Yes: Some people MAY prefer shittier service. Like: Someone CAN prefer to eat a plain McFeast without the burger, just the buns. But they will be paying the same for someone that got some actual meat and effort put into their product.
At the end of the day: We still have someone that can't offer ANYTHING if you ask for a female. And refuse to lift a finger to provide a good service. But will bend over backwards to give you anything you want if you ask for a male.
It's just a lazy hack that charges the same for ex: A broken Playstation 1 as for a custom made PlayStation 4 because "They're both a Playstation, same thing.". It's not complicated. It's black and white. One is less, the other is more.
Again: It's not helped in that it's socially acceptable in the R34 community to be useless at drawing vag. But if someone be that bad at drawing dick, and/or only offered pre-teen human pensies... well, as said: They wouldn't last long. That's a demanded requirement to be able to deliver~