When I was selling high-end woodworking equipment and finishes, there was a day when a California surfboard maker, a Maui longboard maker, and a person making koa mantlepiece surfboards for rich collectors, were in the wait line at the same time. It darn near broke out in a fist fight. They philosophically despised one another.
But this forum is pretty mild in comparison to certain others where one can encounter decades of bitter professional rivalry between
the disputants, each with his own tightly guarded trade secrets alleged to be superior to anyone else's. Reminds me of growing up with an old Indian at one end of the road, and an old white man at the other end, with only a mile between them. Nobody could figure out why they hated each other so much until it was finally revealed that they had been shooting at each other when they were young, with one of them driving the spikes of a narrow gauge RR leading uphill into Indian territory which was still not pacified. That was around 1915.