I'll add my experience from the viewpoint of a small time business owner.
Background: I've run an online Ecommerce business that was B2C and a few software businesses that were B2B.
My overarching philosophy: I don’t tolerate abuse of my staff, my business, or myself at all. I step in any time I see any customer abuse my team and let the customer go immediately. Part of being the owner is I chose who works with us, in the same way a customer chooses who they work with when they sign up for our services. One of the first things I share with new members is to bring any abuse to my attention so I can deal with it.
In the Ecommerce/B2C market, there are a lot more mean, angry, and unreasonable customers. I'd say once or twice a month I'd refund someone and politely send them to patronize my strongest competitor.
In software and B2B, the customers are a lot more knowledgable, mature, and professional. We're all engineers, we're aware things can go awry. As long as we do our part of acknowledging a problem, discussion what we're doing to fix it, and following through, we rarely see that type of behavior.
I think in the last six years I've probably only "fired" maybe four B2B customers, out of thousands and thousands of accounts. Nor do I miss the revenue at all, not in the slightest. Losing $1,500 in MRR is so much better than dealing with bad customers, trust me.
Price does have something to do with this issue too. Like many have said, 95% of our questions, issues, and hassles come from the lower tier price points. To be honest, it’s predominantly from people on free plans, unfortunately. Higher tier price points are usually businesses with competent engineers where value-for-money is understood and any issues are dealt with professionally.
My overall recommendation, again based on what I've seen in my own small world, is to sell something in B2B, preferably B2E(ngineer), with a fair/honest, but not cheap, price point. Fire any bad customer the moment you see abusive behavior. There are literally millions of honest, good, and rewarding business relationships out there. Don’t let bad customers stand in your way to reaching those good customers.