I think people do buy Nikko's discs - or discs he throws. There are people who really support him. And he is a good player once you get past his temper tantrums and rules violations (mainly the time issue).
He might not be a big 'mover' of discs for brands....but that could be due to his not frequently being on the lead card and therefore less visible.
My Opinion here......
Personally, I think we will see a change with Nikko this coming year. He was proven (by Calvin Heimberg) to be taking too long to putt. He's changed brand's a few times....was it his choice or the brand's due to his tantrums, etc? Westside and Nikko just parted ways - so he's lost another brand - while it might have been his decision....I think it was Westside letting him go due to his issues on the course and in social media. Pretty soon, Nikko might find himself without a sponsor if he doesn't improve his act.