It takes a lot of skill to suck as badly as Russell did for the QB position regardless if the team he played for was the Raiders, Lions, or other crappy team.
Ryan Leaf was horrible mostly because he fell apart under the pressure of the NFL and was horrible as a team-mate. Russell managed to outperform Leaf in terms of horrible play style, no passion for football, and declining development.
I say put Russell in the Hall since he deserves it since nobody is going to have the skills to out-suck him for a very long time.