Honestly, I have to sympathize with the hotel. I've seen a few well-behaved kids, but it seems like the vast majority (at least where I live, anyway) are little wild creatures with no concept of how to behave around other people.
I've witnessed the same seat-kicking behavior on buses, and when the victim
dared to turn around and tell the kid to stop, the mom
screamed at her and almost attacked her. I've had parents yell at me for telling their kids not to run around slamming doors in a veterinary clinic, or to stop jumping up and down on the scale.

I've seen kids in stores pull stacks of items off shelves, and the parents just look the other way and don't do a thing to pick the stuff up, much less tell their kid to stop.
My dog is well-behaved and I
always pick up after her, but because a large number of dog owners don't pick up after their dogs, and allow them to pee and poop all over the place and disturb people, dogs are banned in many places, so I'm very limited in where I can take her.
And now there are even fewer places I can take my dog, since she's afraid of small children because an unsupervised toddler ran up to her when I had her in Petsmart and
kicked her.

Thankfully, her response was to run away, rather than bite the child's face off (she's a med-large dog, with her head on a level with the child's), or I probably would have been sued for my dog acting to defend herself. I wish I could discipline those parents for risking their child's safety that way, and for the distress they've caused my dog.
I hope to have kids myself, and am tolerant of a normal level of noise, activity and even the occasional tantrum that even a well-behaved kid can throw. But the little monsters whose parents are completely oblivious to the fact their little darlings are terrorizing everyone? Keep 'em away from me, please!
Just like irresponsible dog owners, the parents who allow their children to behave like little monsters are, unfortunately, spoiling things for other parents who care enough to teach their kids how to behave.