Please for the love of art, no one but the artist has the right to dictate what they can draw. They have the ultimate right to take on or decline requests and commissions as they see fit. When an artist does requests it is because they are chosing to do so.
Artists are not obligated to cater to pissbabies who cannot respect the fact that artists are the ones who are doing the actual drawing itself. If you want an artist to draw a specific thing, fucking pay them. Commission them. But if they decline then that is their right.
They don’t owe you anything if you keep whining and trying to force them to draw what you enjoy. Because guess what? Not everyone enjoys the same thing as you. Give artists basic respect or gtfo.