This is similar to why I started Veggie Kisses. My big motivation, though, was creating a dating site for vegetarians that was run by a vegetarian and not some large company that might run a vegetarian styled dating site as part of their massive portfolio which also runs a variety of other dating sites.
I signed up on a website (I think Veggie Romance) and found out I was added to a pool of websites, including Star Trek Dating and also gay dating. I found my image on these sister sites and was appalled that they would do such a thing and found a checkbox deep in their options that by default posts your portfolio to their entire network of dating sites.
I started my dating site for vegetarians, but mind you, I coded the entire thing from scratch. It still is unfinished, but I was unable to accept payments for it (because dating sites are considered "adult" websites and therefore higher risk and finding a merchant account that will accept adult sites is difficult. I didn't want to rely on a third-party payment processor, so the site became a labor of love since I wouldn't see a dime. As such, it has been greatly ignored in terms of upkeep. Sigh.