Thinking about it, here's what it could be.
(a) Turki has a relationship, a good one at that, with Dana. Business, politics, and tons of other stuff are often founded on that basis. Case in point, Dana and the Fertitas.
(b) Dana White, in terms of image and name recognition seems to be the biggest personality in combat sports, rivaling even many popular fighters. (I'm just guessing; I didn't look it up.)
(c) Turki apparently aims at revolutionizing at least part of the boxing industry, so in that respect an outsider like Dana is not a bad choice.