NOT trying to compete. I also believe that your horse needs to be patient with any problems that you have in mounting. My DH needs a mounting block, and I train his horse to be patient with him.
There is a PC belief that mounting from the ground is harmful to your horse. Ironically, I agree with not torqueing the back bc I have always taught my horses to blow up and hold their breaths when I tighten the girth so that I can easily mount from the ground, and when I am done riding I find my girth is loose.
I happen to believe it is less PC and more common sense, there has been research on it and *shrugs* it's my personal belief that it puts uneeded stress on saddle, horse and rider. YMMV
Still, you are up a creek if you go trail riding, get off and cannot find anything to step on to mount. How ARE you going to get back on? Will you lead your horse back? This is a question you need to answer, and the answer to this should guide your horse's training.
BUT the op was not talking about trail riding, they were talking about arena riding. As to me, IF I have to get off on the trail, then yes, I would have to lead my horse to something that I could utilize as a booster to help me get back on. This is only going to get worse in the 5 years the surgeon gives me before I need a replacement. My horses ARE trained to stand by a block, and wait patiently for me to mount.
Also, I personally believe in this shrinking horseowner market that you cannot overtrain your horse. A well trained horse will always find a buyer and stands a better chance at finding a new and good home, especially if he or she has special skills, like laying down so you just step onto the saddle. =D
A well trained horse will always sell better than a poorly trained one, and one that is trained to stand quietly by a box, stump, fence, wobbly bucket or any other thing you can use as an aid is a big bonus in my book.