I never like the Cubs, but I liked the Sox. The Sox were the working class's team. The Cubs were something else.
There were some awful Braves and Pirates teams in the 80s that might rival this year's Sox. I seem to recall a particularly abysmal Devil Rays team at some point.
Not MLB, but there were some atrocious Pacers teams in the early/mid 80s I rooted for. It was all supposed to change when they drafted Wayman Tisdale. Great guy, good player, but not even close to a franchise player. Then they drafted Reggie Miller and put the pieces around him to be a contender. Naturally, the fans booed when Miller was drafted. They wanted Steve Alford, who made Rick Mount seem like a pro hall of famer.