A few years ago I hired a TS to be the receptionist for our accounting firm. She was extremely fashionable and good with people, but a little slow on the technical side. Even though I really liked her, I eventually had to let her go because some of my biggest clients found out and threatened to take their business elsewhere. If she had been more technically competent I would have considered keeping her, but in the end I had to put our finances first and gave in to their bigoted hatred.
Another time I picked up a handful of clients who were looking for a new accountant because they found out that their former CPA had announced that he was transitioning. I had to smile because I'm sure they had no idea that their new CPA was also a cross dresser...
Bottom line is that although we all try to be as accepting as possible, we are a minority doing battle against a larger public perception. We sometimes have to put the needs of our businesses and our customers first. If a TS applied at my firm for a back office position, yes, I would hire them in a minute as long as they were technically skilled. But it get's a whole lot more complicated when hiring someone who is going to be dealing with the public.
Heck, even I sometimes wish I could come to work in a dress, but I remind myself that presenting as male at the office is just like wearing my "uniform" at work. It's not what I would wear at home, nor is it who I really am. It's just a roll I play in order to make a living.