On Role-playing True-to-Canon Elves Despite Fellow Players Promoting Orcs

While I have read all the 3.5 sourcebooks — and had some practically memorised, I haven’t played that many campaigns. One of the few that I did, I went with a Lawful Neutral Grey Elf Wizard, and as part of my backstory wanted my character to be very conservative and traditional, and entrenched in his beliefs, steeped in that which was important to Elven culture, most specifically including the Elven hatred, loathing, contempt, and desire to utterly expunge the Orcs. I felt it meshed well with the rest of my backstory, with our campaign setting, and with the campaign details I was given. However, unbeknownst to me, another player chose to be a half-Orc. This would have been problematic were it not for the fact that his love of leaping into combat got him killed right off the bat, but his replacement character, a human Paladin, chose to make it his mission to proselyte to and convert the Orcs into law-abiding beings, while one of my long-term goals was to eventually cleanse the Material Plane of every last drop of Orc blood. I chose to roleplay this and take the conflicting dynamic as an opportunity for immersion, but my fellow players grew rather frustrated by my character’s unwillingness to give up his heritage for another’s whims, and the scenario collapsed before any solution arose. I am not trying to argue that Orcs shouldn’t be considered capable of alignment shift or civilised behaviour, or that my character’s actions were Good (his moral component of alignment was Neutral), but how does one reconcile character motivations that conflict in a manner where for one to succeed the other must fail? Do we go by precedence, allowing the Elf’s mission to succeed because he was around longer? Do we choose by dragging modern era moral systems into feudal societies and ban canon racial hatred as racist, despite how very pertinent such attitudes and behaviours were in those societies, thus removing part of that aspect of realism that makes the game so well-beloved?