...hummm...hope I'm not near your hospital, doc.
Seems to me that if it's a one-off, first time, then it happens. Bad luck. We all understand. No problem.
But if I know that (for example) I'm afraid of spiders, I may well want to get over it, but I probably ought to do it in a way that doesn't inconvenience 50/100/200/300 other people.
And if I am running a business that depends on people being OK with (insert potential scary fear here) then it's reasonable to expect that people suffering from (insert scary fear) might want to reconsider their potential to disrupt the lives of lots of others by, nonetheless and in spite of their known fear, interacting with my business.
Further, if I know that they are suffering from said fear from previous experience it seems reasonable that I should at least have the option to decline their business. This has nothing to do with human rights, victimisation or prejudice.
Most people don't travel for the enjoyment of travelling. Whether they are going on holiday or on business, most people have deadlines/timings to meet. It seems somewhat discourteous to put so many others to inconvenience in those cases where someone has a known and unresolved fear that may or may not rear its head.
Like most things in life, this is a whole lot simpler if people just act responsibly rather than there having to be laws and regulations in place.