My thought is there isn't really one or two archtype of rep owners. Sure there are d-bags who buys replicas of prestigous brands to show off, but then what is the difference between a d-bag who buys gens for that same purpose? On the other end of the scale, there are people who likes watches and appreciate what the replicate represents; and at rep prices can acquire a lot more than they otherwise would with gens.
As for myself, it is hard for me to justify why I like the rep watches the way I do. I can go on about a brand's history and pedigree and how much I admire that company's history and horological innovactions, until I stop and tell myself what I am wearing does not represent any of them since they are fake. I sometimes refer my reps as "toys" instead of Panerai, Omega and Franck Muller because they are not Pams, etc. The answer I come to is that I simply like my watches as they are aesthetically pleasing to me, not for the brand, history, etc because then I am only lying to myself. As an aside, I also realize 6 months into this hobby, I spent close to 3,000 in straps, mods and watches. At this rate I could have gotten a used genuine in another 6 months!
As for the OP's original question, my guess is that rep owners dislike rep owners for the simple fact rep owners acquire something they know is not genuine. Fair or not, this implies a certain degree of dishonesty. One can view acquiring reps and passing them off as gens is another "short cut" in life. Owning genuine watches suggests the owner had reached certain achievements in life and the very existence of replicas cheapens that sense of accomplishment.
Just sharing my simple view of the world...