In the United States on the federal level, it's against the law (and most people would agree should be against the law) for business owners to refuse service to members of the public who happen to be Black, women, pregnant, from a foreign nation, disabled. etc. The civil rights laws that bar such discrimination rose from the grassroots calls of the 1950s and 60s Freedom Riders as they traveled the south "sitting in" at restaurants and other pubic venues that didn't serve Black people.
The proposed federal Equality Act would add LGBTQ people to the larger list of "protected classes" of people private businesses owners are legally barred from discriminating against.
Many states already have nondiscrimination laws on the books that include LGBTQ people, but Michigan is not one of them. I learned after I published the story, however, that Grand Rapids has a city ordinance barring business owners denying service to people on the grounds of sexual orientation or gender identity. A petition is circulating now with over 15,000 signatures asking the council to enforce the ordinance by pulling the business license of The Broadaway Avenue.
I hope the the effort suceeds. And I hope you understand you're mistaken when you claim private buinesses have the right to refuse service for any reason at their own discretion. That's not true in the United States at almost any level. The only question is should LGBTQ people be protected from discrimination like other very large groups of people.