Yes, DJI do dominate.
No they don't. That data is for US drones
used for commercial purposes in 2014, based on dollar value.
But the vast majority of drones today aren't being used for commercial purposes. And using dollar value doesn't correlate with the number of drones actually being sold (and flown) in the market.
For every DJI drone there are probably 20 more drones sold by companies like Syma, UDI, Hubsan, etc.