How would businesses be more profitable if they exercised the right to refuse service more? You also realize the people who exercise this right the most do it for reasons you likely don't agree with.
Maybe they use a lot of a free service you provide that costs you money. Maybe they require too much customer support. Maybe they return most of the products they buy from you. I've looked at a few datasets where profitability by customer varied pretty widely, including many that were clearly in the red. Most companies just don't break out their costs by customer enough to see it.
If more companies were forced to pause and consider whether taking on certain customers would cause their workers to revolt, we’d all be better off.