It may be stylistic. Cuban tends to opine a lot and sometimes comes across as a blowhard.

He's overexposed too. There's something about people like Gates who don't make a lot of public pronouncements. When they speak, you tend to think it's because they have something of value to say (and they generally do).

Probably doesn't hurt that they also let their work do most of the talking for them (e.g. Bill and Melinda Gates Foundation).