Fairly or unfairly, Marvin Harrison has been linked to three or four shooting incidents. He admitted to owning a gun that ballistic tests have linked to one of the shootings. One of the plaintiff's who sued Harrison over one of the shootings was later shot again near Harrison's bar, and died several weeks after the shooting. Just last summer, Harrison was shot at after he claims to have rescued a guy being chased at 3:00 am.
I'm not sure the NFL is anxious for Harrison to be voted into the HOF.
As for Brown getting in, I suspect he was given credit for being a punt returner as well, and for doing as well as he did with about a dozen starting QBs during his career, including Marinovich, Hostettler, George, etc. Anyone think he might not have had much, much better stats with P. Manning throwing to him?