Because there's no good reason to kill JK and because JK has been fairly active so far. The reason JK was wagonned was due to a completely innocuous vote on Omega. The reason Omega was wagonned was due to perceived defensiveness. Neither of those is a good reason. Omega vs. JK looks like hot vanillager on vanillager action, though since its D1 I can't be sure.
As for why KM?
Throwing KM onto the pile made three good contenders for today's lynch, which generates more interesting EOD results. While as I've learned the hard way, ties are not perfect tells, their still decent information sources. Better than runaway wagons or random 1 to 2 vote distributions. Also KM has posted far less than JK or Omega, and I'm not getting Arakhor, my top choice, lynched today. Or BSmith for that matter. I like Duff's case on him, but its too late to make it happen.