If they delete a profile, they actually delete it, not just make it look like it is to a select few users. What evidence do you have that the requests from deleted profiles AREN'T spammers?
I mean, seriously, if you're getting 5 requests a day, they're already going to be teenagers or shitty local bands who don't know you personally and just want more friends to look popular (omg, I just cracked the Myspace code), with a healthy contingent of spambots. 3 of 5 sounds about right.