Skateboarders treated as second class citizens

Today, I was skating a seven set in London, when I experienced one of the weirdest kick-outs I'd ever experienced.

 Me and some friends were skating this seven on Thames Path. It's a seven set on a through path, which links the pathway to the main road, so doesn't really belong to any kind of building or block of offices.

 It was around 6 p.m. in the evening, possibly closer to 7 p.m, meaning all offices were shut down, and there was no-one using the stair set. For what its worth, the place was desolate.

Only two of us were actually skating the set. It had been a long day, and everyone was tired, but my friend and I kept going at it. "Skate 'til death", right?

 Anyway, soon enough, this security guard came out. He wasn't pleasant. He barely spoke English. He just waved his hands like we were some irritable pest, gesturing us off the "public property" (I thought it was private property that we were meant to get kicked from?).

We were tired as hell, so we were just like "Give us a few minutes to sit on the grass, we just wanna chill. We won't skate". Maybe he's heard this a few too many times, but it was a bit of a joke when he told us "No-one sits on the grass. This is private property. Go. Go now!"

This had to be a joke. Only six hours earlier had we passed this same spot at lunch time, and decided not to skate it as people were eating lunch on the grass and having fun with their friends. We were being the considerate ones! We come back at an anti-social hour, and we still get kicked! And then we're not allowed to sit on the grass, when people had been doing that all day! Harsh or what?!

 The real irony is, as we left, a young lady, around 20 years of age, parked herself down on the grass and started eating a sandwich. And yet our good friend who couldn't speak English hardly ran out of his building to shoo her away, in the "Get off my land or I'll kill you" manner that he used with us.

My question is "Does carrying a skateboard really prohibit us from many of lifes luxuries, like sitting on the grass and chilling out by the cool London sunset, sharing a few laughs with your friends, and grabbing a drink before the long treck home?"

Obviously, some security guards need to chill out and start treating skaters as the talented athletes we are, especially considering we treat others with respect by skating at anti-social hours and complying with unfair rules constantly.

How do you believe we, the skater, or "the public enemy" should deal with security guards like this, without aggressive (verbal, physical or violent) behavior?