He's a legitimate NBA rotation player (nothing special) and having 6 of those guys instead of 5 is important especially considering it was at our weakest position in terms of depth. And his play style fits our philosophy. Super athlete. Perimeter oriented 4. Defense. Hustle.
Ultimately he's available for a reason. He's got weaknesses. Not an intuitive player. But stocking your cupboards with flawed hustle guys is a good way to get cheap wins in the middle of a season. That's basically how Chicago won 10 out of 12 on a stretch.