I've seen that rule of thumb applied to nearly all the pairings of PW. Common examples being that a Phoenix/Maya supporter is a yaoi-hating obligatory hero/heroine shipper, Fran/Edgeworth supporter is a yaoi-hating ignoring-familial-bonds het shipper, Fran/Adrian is a jump-at-yuri shipper, etcetera etcetera. I'd swear the only one to not get that kind of reply is Gumshoe/Maggey because it doesn't interfere with any huge ships/is pretty much canon.

So it's just stronger with Phoenix/Edgeworth because it's prominent? I always got the feeling that P/E supporters were supposed to be the 'cool sane' ones of the fandom. How fandom changes.