To me it is one of those things... Just because you can and just because it's legal don't mean it is right or smart. There is no shoulder on MLK so you are forcing auto traffic down to one lane and it is much too busy for that during the morning commute. It just pisses people off who are probably already in a hurry. Bad idea. If you do decide to do it you best take the entire lane because cars will try to squeeze you between them and the curb.
And yes, I would suggest auto traffic take an alternate route if the most direct one is not safe. 3 blocks out of the way and 5 extra minutes are well worth the inconvenience. That seems to be the difference in opinion here. I do not feel riding MLK during peak high traffic is safe.
Why would you not ride down it "personally"?