Some people are fans of the Tennessee Titans. But many, many more people are NOT fans of the Tennessee Titans. This 2012 Deadspin NFL team preview is for those in the latter group. Read the other Why Your Team Sucks 2012 previews here. 1. Chris Johnson, you are fat and shitty. Every running back who has ever lived should find an airtight rubber box, take a shit into it, and ship that box to either Chris Johnson or Marshawn Lynch. Between those two idiots, no rational GM will ever hand a starting running back $30 million guaranteed again. Cop Speed scored one-third as many touchdowns in 2011 as he did in 2010. His YPC dropped to 4.0 (after a high of 5.6 during his amazing 2009 season). Not once did he do that thing where he takes a little swing pass and then hits the NITRO button and the…