I don't see why being "in business" should be the high-water mark.
People tear down others when they, themselves, are lacking. Being "in business" doesn't make it any more or less palatable.
It is stupid to pull something like that while you are in the business related to the field because it has far more chance of coming back to bite you exceptionally hard.
My day job is in software development. If I bad mouth a photographer, and word gets around photography community/industry that I did something that low, then it is rather unlikely to have much of an impact on my career overall. I'll keep getting jobs in programming, and drawing contracts from around the globe.
However, if I were a fully time photographer working in a community, and people got onto it that I was a hack of a photographer and less than pleasant to work with, then my income is then on the line.