Wait, what's the logic there? I've seen pads help a lot of thin-soled horses on soft ground, like in a sandy arena, to prevent bruising. It sounds like @barbaramurphy is onto something about rigid rules missing the point. Isn't it more about the specific situation, like what surface the horse is working on, rather than a flat ban?
Hold on, you're using pads on a sandy arena? That's the part that gets me. Sand is already soft and giving. Putting a pad on top of that just creates a weird, unstable squish layer. It's like walking on a mattress. No wonder people are seeing problems.