People flock to the religions that promise to satisfy their deepest desires. You can argue that so-and-so follows a religion even though it's clearly not conforming to so-and-so's desires, but what do you know of so-and-so's desires? Regardless, if I remember OoE right, they go back to this little spat. Drac is just a tool -- certain parties have turned to him as a messiah for them. His powers and abilities while not directly affecting his "believers" still convince them that D can satisfy their deepest desires. In that way he has become the focus of a burgeoning religion. Richter seems to imply that D is pulling the strings, but D is saying -- and this was recapped in OoE I think -- that he wanted no part of the foolish religion, but since the role has been cast upon him he will take up the mantle. In essence, he's the antithesis to Brian from Monty Python's "The Life Of Brian". Whereas Brian was adopted as a messiah and tried to avoid it, D accepted the role but chose to wield the responsibility his followers endowed upon him in his own way rather than what they mayhaps hoped for. So he's saying, "I'm just here, summoning demons, minding my own business. Don't come running to me looking for someone to blame; look around you if you ever leave the castle alive." Dracula was specifically summoned by cultists (Templars?) when Richter confronted him, so his claim is valid and Richter is thus the instigator and misguided antagonist in this situation.