Millennia of imbalance towards men having the upper hand in just about all societies is a plain fact.

However, progress and equality is not the reversal of an imbalance - it's the leveling of a playing field and accepting that to achieve real meaningful change, the notion of retribution must be taken off the table.

Either it's ok for both genders to have a service like this, or it is not ok for either gender to have a service like this. End of story.

Personally I'd find any site like this reprehensible for either gender (or any other biologically or socially discernable metric, for that matter).