I have no objection to the website operator wanting to cater only to people who want serious relationships, but calling flings and hook-ups "smut", with the implication that people who engage in such activities are "smut-makers", is extremely unprofessional and disrespectful, to say the least of it.

In addition, there are many people who are open-minded about casual sex but want serious relationships, perhaps with someone who shares their values on sexuality, but these people will have been turned away (as well as their not-so-open-minded friends who think the operator has no right to be a jerk toward their friends), thus reducing the usefulness of the website altogether, not only for those who have such values, but for anyone who might have otherwise found a good match with them or their friends.

In general, promoting your business as inclusive and caring while tarnishing the reputation of your previous employers and insulting other people have done no wrong to you is more than a little hypocritical.