Shuned based on breed...?

I do PPT with my 1 year old male reg. intact Cattle dog Rocky. We have ped the obediance training really fast (i do formal training at home) so it was just a run though mostly while working on somethings. We are on level 2 training ( a href="http://www.mrazovack9.com/us/pricing.php?lg=us" rel="nofollow"http://www.mrazovack9.com/us/pricing.php…/a ). Our cl has 6 dogs (4 GSD, 1 Boxer and 1 ACD(mine). Me and Chris (boxer owner) both get treated rudely, insulted, critized by the 4 GSD owners. When we asked them why, we were told 6 reasons why we shouldnt be training in this disipline with dogs "not bred or inferior for this work". Is this the norm when going into a breed spicific dog sport? IMO any dog who can do the work and do it PROPERLY, should be able to do it.