Prove it,for my chain lube I ran motor oil both used and new in my saws for over 30 years,I never had one incident of a failure from using it. Where is the potential to damage your machine? I can see the possibility of shorter bar life,though I have never noticed it. You believe that Bar and chain oil is for you go for it. If someone wants to run other oil thats what works for him.
That biodegradable oil from Bailey's is really Veggie oil with additives. I have read where lots of folks are veggie oil on their bars.
Here is a good link about using Veggie oil in your saw:
http://www.earthenexposure.com/permaculture/chainsaws/vegioils.htm
I have probably well over 100 gallons of used Veggie oil,I may clean it by filtration and try it in one of my older saws. I have never done this,but if anyone here has please post your results.