The NBA is predominately black, mostly Democrats. You saw the pro-Obama love when he was in office, it just turned 180 with the new administration.
By my count, Kerr, Pringles, SVG, Pop (several times) and Doc have all throwing their political opinion out there.
NBA's Gametime anchors have done it too. Very disrespectful, imo.
Players include LeBron, Melo, that kid from the Nets, Shumpert, JR Smith.
Guys like Randle and Westbrook I respect a lot because their response was basically, "I didn't vote for him, that's all I'm gonna say." I think Randle even implied he may have voted the other way
As far as anchors goes, there's a few neutral and even redpilled ones. /ourgirl/ Cassidy Hubbarth is a good example.
To answer your question, why are people throwing political opinions out, it's a result of Adam Silver pushing the NBA as a progressive league. While few will argue that pushing out Donald Sterling as an owner was a bad thing, it has given way for the league to go farther and father down the social justice route.
They then removed the All-Star game from Charlotte, absolutely unwarranted. I feel a lot of this was caused by 1) the fact the NBA feels the need to cave to so called "social media pressure" and 2) Adam Silver is a closet homosexual.
Now, I feel the NBA is in the uncomfortable spot of having to respond to each and every social crisis that happens. Somewhere along the line, they forgot that they are entertainment and not Red Cross or the Salvation Army.