A bit of both I think.I wonder, and please take this as constructive, do they think side mount is dangerous, or do they think you are dangerous? It might be easy to confuse the two when you're so close.
Had they been able to get me to try backmount it would not have bee as big a problem.
Would have led to me repeating that each time I met a new one, probably - so I never gave them a chance and they took this badly most times.