I don't see a problem with it. Brake lights don't illuminate when the handbrake is on, and I'm not aware that there's anything bad about sitting at traffic lights using the handbrake to keep you stopped instead of the footbrake. As a driver, If I'm at the back of the line or the only car stopped I might keep the footbrake on to make sure approaching drivers know I'm stopped, but in a line of traffic no reason to.

Only a certifiable moron would watch the brake lights of the car in front of them to see if they are at a complete stop at an intersection. Your analogy is not valid, I have already signaled that I'm braking and at a complete stop and will begin forward motion when the light turns green, which the motorist behind me is looking for too. What about a driver that puts their car in park at an intersection, does this confuse the other drivers too. Just because you can't do a decent trackstand without falling over and scaring everyone around you doesn't mean you should make up nonsense reasons why the rest of us who can shouldn't do it.

Next time there's a cop car beside you...lean on it and see the reaction you get. It would be like me stopping beside you on my bike and using you as my means of staying upright...you'd be ticked.