I will never understand why people believe rolling on something other than a mat makes BJJ useless. I have rolled on concrete before. For some reason I also regularly roll on marble floor every time my friends and I get together for a UFC. It is uncomfortable, but unless you are fighting a wrestler or Judoka (or MMA practitioner), the hardness of the ground is not something you need to worry about much at all, and if the other person knows nothing about groudwork, they're the ones who have to worry about the ground, not you.
I've grappled on concrete before.
Sure I had some scratches and stuff.
But guess what? Mat burns hurt more.
The mat burns/scratches etc. Are probably worse than what you will get grappling on a sidewalk.
Now, on asphalt in the highway, it's a different story...
The guy in the original video explaining why grappling is bad is Todd Keuneke. Recently I was looking at a couple big JKD guy's face book pages and noticed him posting on their walls, in all caps, that he tried to join the Larry Hartsell grappling association or something. And was apparently ripped off for twenty dollars, lol? He then went on to call Larry Hartsell's wife some unflattering comments.
It's safe to assume hes trying to learn grappling now but doesn't have the balls to walk into a BJJ gym.