You can't get a trait like this without it being genetic...phenotype is just expressed genotype....even if being rootbound is the cause of expression it is still genetic...it's just that the rootbound environment is causing the expression.
True the climate is stable at the moment and has been during our evolution, but it's kinda beside the point...we could only have evolved when we did because our ape ancestors existed then...you go back to the cambrian or something and it never would ave happened as life hadn't developed to the...
I honestly don't know how you'd deal with it... with so many possible causes, you'd have to identify what's causing it before you could know what to do.. I've never had the issue myself, just seen galls on other plants when out and about...
I imagine it would be a useful place for commercial growers to brainstorm and get/share new ideas..think about things from different perspectives...for me it wold just be interesting to see what's happening in the world of large scale growers..!