Now that I have more than a passing minute . . .
I do have to ask, Dawger, if you had been asked to please stay out of the 1v1, whether you would have done so out of courtesy, or continued to carry your "it's my $15 bucks" attitude and stolen the guy's kill anyway? If you would have respected the request, great, that is a fine attitude to bring into the AvA (or anywhere else in AH). If not, then I have to say that IMO the "to hell with you, it's my $15 bucks" attitude is no better than those who expect you to fly by certain rules.
The numbers in the AvA are often too low for there to be a proper "fair fight." This is why many of the old timers cling to their "rules." Think about it -- if it is four on one and the four constantly dogpile, there is no reason for the one to stick around. He will leave, and the four will have nothing to do but look at each other. (After all, which of the four would dare switch when they know they will simply be on the receiving end of what he was just dishing out?) So, better and longer lasting fun for all if the four limit themselves to either 1v1 or 2v1s at most so their opponent at least feels like he has a chance, and therefore keeps upping.
Once the numbers are up a bit and there is a proper little furball going, then of course all "rules" are off. I don't think there are very many old timers who think that 4 planes running headlong into 4 planes must necessarily become 4 individual 1v1s. But three guys flying over a 1v1 in progress should have the courtesy not to dogpile IMO. That doesn't make it a DA by a different name, but does make it a place people can enjoy themselves. If they don't, they will leave.
Which is to say, the "no rules", anything goes atmosphere you espouse is just as likely if not moreseo to drive off newcomers as some artificial "rules" might.
All that being said, you certainly could have been approached in a more polite manner; but given the immediate hostility of your response, I suspect you would have responded just as impolitely in any event.