Yes I'm one of those parents. The ones that let their kids go up the slide. I try my hardest to emphasize the importance of only going up when there aren't other kids around, or when they're not near your particular slide. It doesn't always work, but I try.
That disclaimer is simply to reassure you that while I'm trying to raise respectful and courteous little people, I also encourage their daring behavior to some extent.
Witness my 10 month old crawling up the slide:
Apologies for the sideways video and lack of sound. My little point-and-shoot camera takes pretty crappy video but that's all I had with me.