Jones isn't too big for the division... most of the other fighters in the division are too small.
There aren't many guys in the fight world that are athletic and 220+. This keeps the LHW and HW divisions thin on talent. It makes for an easier path to a title shot for natural large MWs to fight in the heavier division. Since there are even fewer 240+ athletic guys out there, Large LHWs have a better chance at a title shot and more $$$ in the more prominent division. So, it keeps the LHW division naturally depleted of Large LHWs.
The fact that nearly all of Jones recent opponents save Glover/Gus are now fighting at MW or have seriously considered it says plenty.
There aren't many guys in the fight world that are athletic and 220+. This keeps the LHW and HW divisions thin on talent. It makes for an easier path to a title shot for natural large MWs to fight in the heavier division. Since there are even fewer 240+ athletic guys out there, Large LHWs have a better chance at a title shot and more $$$ in the more prominent division. So, it keeps the LHW division naturally depleted of Large LHWs.
The fact that nearly all of Jones recent opponents save Glover/Gus are now fighting at MW or have seriously considered it says plenty.