Now why would Boonex want to tell people not to create dating sites with Dolphin; the last time I looked, Boonex was making money from people creating dating sites with Dolphin.
7 billion people. Every one is capable of joining at least 10 sites. 70 billion "members" - that's 100,000 members for every site you've mentioned. Convert them at 10% with 10$/month membership, and webmaster gets a nice 100K/month income. All good. :)