Because he's a golf guy, this is made worse, as Alma pointed out. The fact that he didn't think through what he was saying and hold back before giving it a little more thought in order to realize how it actually would come off didn't help.
I can actually see his point. I'm not sure he was trying to be funny, and can believe that he was, in fact, attempting to make a point about the, in fact, overwhelming success of Koreans on the LPGA Tour. The problem is that he made it badly, and thoughtlessly.
The other problem is that, there is almost no way to speak to the phenomenon without sounding like a racist jerk in some way. It doesn't mean the phenomenon is not going on, though.
As to the way he characterized the status of the LPGA, I would compare it to the way people see the WNBA in comparison to the NBA, and in that, the parallel is, in fact, accurate.