My pony doesn't do all
disciplines, but people always tell me I should be doing something else with him LOL. For example, I have been "stuck" competing in hunter shows and everyone that sees him either says he should be doing barrels (mainly because he has a MASSIVE brand on his HQs), or eventing.
The weirdest one I got was, someone said he should be a polo pony
They wanted to buy them for their polo barn too, I was like NOOOO! Lol.
From the sounds of it though, maybe these people saying your horse is going to get injured because they are jealous?
Or if your horse is young, maybe they think he's just being worked to hard for his age? I can't really say much about that though considering I don't know how often you ride your horse and such.