But let's get off our pedestals of moral superiority for a second and get real: some people are extremely visually beautiful, while others aren't. This does not speak to their inner beauty or personality, this is just about physical attractiveness.
And let's also get real about the fact that some people are vain or have high standards and as such, will only consider dating other beautiful people (9s or 10s). This is a fact, even if it seems wrong to the rest of us.
And let's also get real about the rights of private services. They have the right to set whatever criteria they want. Because they're just ONE of MANY options. There are plenty of other all-purpose dating sites out there, why should we care if one is vain and shallow? If people want that sort of service, doesn't the site have a right to provide it? A strip club has the right to refuse ugly applicants because that feeds directly into their profits (clients don't want to see ugly women strip).
I understand and agree that this practice is shallow and disrespectful, but I also understand that there is nothing compulsory about it. We can choose from plenty of equal-opportunity dating sites, so there's no point in getting worked up about the few that have exclusive criteria or unusually high standards.