He was paid that amount of money to be a NT his job who's job is to take on blocks and stop the run. He did his job.
He didn't do it well enough. Ted Washington was playing at a higher level that he was in 2006. We could have picked through a bunch of old NTs and late round draft picks if we wanted somebody to take up blocks.
Kris Jenkins was the real NT who actually made a difference against the run even when he was fat/disgruntled. Not saying that Kemo was expected to be Kris Jenkins but he's overated even just saying he's supposed to stop the run and take up blocks. He was paid to be more than that.
Damione Lewis was a much more successful signing. It was a given he was a pass rusher and that was it. He did a decent job rushing the passer and he also didn't fall off the face of the earth once Jenkins left.
The defense was an absolute mess without him but that's what they get when the FO just absolutely ignores DT for 3 years. Nick Hayden is no Kemo. Letting two one demensional DTs be starters was a bad, bad idea with no depth was pretty much an awful idea.