Here here!
I was a marshal back in 1989 -1991, and had a great time and everyone responded well to polite requests to move or behave.
When I came back in 2006 I found some spectators a little more resistant and intent on defying any polite requests.
I haven't been back since, but it sounds like the new generation of spectators/visitors contain a few more bad apples than in the past.
I hope this trend doesn't continue.