A few thoughts:
People can be dumb, not thinking about how appropriate it is to modify any spot. How visible is it? How many people skate it daily? Does this spot need
Some help? Or is my skill diminished and I think the thing I’m doing will magically make me better at skating? Curbs, ledges, rails etc are subject to a short term mindset by modifying the spot and raising somebodies attention and then ruining it for everyone.
Obviously waxing/sealing a sidewalk a foot and a half in is pretty ridiculous and yes most times an extra push will solve your 6” slappy problems. But with 4 months of rain when curbs here lose that initial layer of paint and the seams start to erode the curb is on its way out and when it’s a spot no one is paying attention at I’m gonna do my best to ensure it will last a while. Not to mention make it way more fun to skate. Most people have little forethought into circumstances and ruin it for everyone.
It’s a case by case thing, don’t just pour sealer and wax on everything.
Sorry about your spots, that always sucks.