@ Boneshaker: Thanks for even asking the question, you beat me to it, your comments here are exactly my same thoughts: "Just because you can and just because it's legal don't mean it is right or smart." "And yes, I would suggest auto traffic take an alternate route if the most direct one is not safe."
My usual concern for the people I see riding on MLK is their safety.
I haven't seen the group ride on MLK and it would seem that there would be better safety in numbers. But I'm always so concerned for the solo riders I see on MLK, and I question if they are trading convenience for their safety.
We see all too often that a minor error on a drivers part can mean a tragic fatality for those of us on 2 wheels, regardless of how safe the bike rider is or isn't. From my perspective riding MLK seems to be inviting danger simply by increasing the odds of aggressive traffic.
I'm certainly not going to suggest where people should or shouldn't ride their bikes, but I will advocate each one of us putting an extremely high value on our own personal safety and taking as much personal responsibility for where we choose to ride.