Yeah, just to state my full opinion here, I believe a few things.
First, I think that park fans in particular should probably be
extra careful to be gentle with and respectful of park property.
Second, I don't think using an umbrella as a means of physical stabilization probably fits within that "be extra gentle" philosophy.
Thirdly, I believe that high traffic, public spaces like amusement parks should probably be built to a level of resiliency (wherever possible) as to allow them to withstand a fair amount of abuse from often rude and rowdy guests.
Fourth, like
@halfabee said, I think that, especially in the case of a vertical pole placed in the middle of a 180° turn in a path, it is fairly obvious that said pole will need particular reenforcement.
Fifth, I think that security grilling and now banning a guest over a broken umbrella in a high traffic location that's part of a building that keeps falling apart on its own seems pretty disproportionately aggressive to me.
"Swinging" around an umbrella pole as you round a u-turn? Probably a bad idea. I would encourage people not to do that. Being banned from the park because it happened to break when you did it? Baring some evidence that there was an intentional attempt to be reckless and break something, that response seems pretty extreme.