Why there are so few female customers of male sex workers?

[Sir Mohamed]

Because most women can get much easier without paying barring the possibility that they're very unattractive.

Naturally males (humans and animals) have to apply to females, who select their partner.

However, I wouldn't say women want it less in general (but some studies showed that women aged about 40 want it more than younger ones), but they usually prefer to have a deep relationship with a partner. Men are different; often, not always, they more care about looks and attractiveness.