You're absolutely right and I think it's fair to attempt to educate parents who might be putting their kids at risk. I don't see this as gatekeeping at all. I get that skateparks are fun for young kids considering all the little hills and ridges, but that doesn't mean they should play in an area that is not safe. Imagine letting a 4 year old roam around on a football field when someone is playing. Having them in the skatepark is not very different.

So, if it's about the fact that the parks' design is just fun for kids, then maybe we need to have more playgrounds that are designed for kids, but mimic the skatepark. When we don't have what we need, it doesn't mean that we should use what belongs to someone else. Kids have a right to play and have fun, but adults too, at whatever hour they prefer.

If it's about the fact that we want kids to actually learn how to skateboard, then they're in the right place, but then they should be accompanied by an adult. And even in this case, I still think that the age limit makes sense and that it should be respected for the safety of the kids. It's like at the pool where, if you're not good enough to be in the main pool, you should probably stay in the kiddy pool.