For those on the side of the OP/the idea that it's ridiculous for a horse to be spooking at the pram (need to desensitize, train better, etc.)... have you really never had a horse just loose it's mind or be honestly terrified of something?
Yep and I had to show anyway. I do reined cowhorse. My 5 YO mare is still green in the show pen this year. The last two shows have been HUGE so our class has been at night. The facility we show at does not have lights in the main arena, so they have to bring in gas powered lights. They are big. They are loud. And they are bright. They cause shadows in the arena because of where they are placed. My mare DID NOT like them and was terrified of them. The first show she started backing up REALLY FAST when we started going into the show pen and only went forward with a little assistance from behind.
Once in the pen, I could feel her shaking and she was not listening, but I urged her on and we got through the reining pattern the best we could. Was not pretty, but oh well; we still got a score though! However, when the cow came out, she was a different horse and we got the best score we ever got.
The next show was also huge and we had to show under the lights again. I took her before our run and hung out by the lights and worked her a little on the ground around them. She was still nervous and we did not have a good run (she was extremely nervous in the reining portion & I lost focus on the cow and it got by me
). But the whole point was to get her listening to me; it will likely take a few more times, but we may not have to show under the lights for a while.
She was also freaked out by a pony at a play day. But again, she is still required to listen to me and work when I ask her. It's not pretty right now, but she's getting the idea that when I ask her to work, I take precedent over the scary object. It can be done (and is done all the time), but if others choose not to work that way, that's up to them.
I work my horses mainly at home. There are little distratcitons there so when we go out, there are major distractions. It doesn't matter the type of show I do (I occasionally do other shows than reined cowhorse), my horses still need to listen to me.
I side with the OP. She was OK with moving at least twice (which appears to be to accommodate riders, not for safety per se) and accommodated the requests even after that, until it got way ridiculous and she felt her only option was to leave. I think that's pretty sad.