Many people like Andreas don’t see them as a threat, but companies are going to settle for the chain that just gets the job done whether it is public or not.
I really buy Andreas' analogy that private blockchains are like corporate intranets. They really have nothing on the Internet, they're limited, fragile, and more-or-less useless. It doesn't hurt to explain the benefits of public blockchains, but people are going to come around sooner or later, because of those benefits. The fruits of liberty are just too great.
Anyway, I agree with your thesis about quitting the infighting. It's like people say, "You're down on whatever you're not up on." When money is involved, people try to tear other projects down. I'm not sure if there's an easy way to prevent that, as people are always going to get emotional about money.