Probably because they are paying for the poll that they are touting. Would a Cadillac ad ever mention a Lexus -- and say it is a better car?
(Most polls -- even the bad ones -- show more intensity on the Republican side. If this tells core Democrat voters that Hillary is a shoo-in so they can open a beer and stay home, that's fine with me. Hillary has trouble drawing flies to her rallies, so I believe the voter intensity results.)
Fox polling agency is located in Boston, last I knew.
Enuf said.