@YBGuy this reminds me of when I got my business license for my motorcycling interests back in 2003. What made me do it was I had to have one in order to access and participate in trade shows. Plus when I was customizing and working on bikes for people, getting the business to business pricing was good.
My county clerk asked why I just did not claim the small income after expense as a hobby vs. paying the license fees and taxes on the income. I explained the need for the license. The kindly old man laughed and said he called that a "legalized hobby" because he ran with some car nuts that did the same.
I too have regular income streams besides motorcycling and there have been years where the shop or channel were just money pits after all the expenses. They just were not like that several years in a row because of what you said - IRS does take an interest when they think they don't get theirs.
Having a business license does help hold me accountable at times and makes things more legitimate.