Because they agreed to it and are getting compensated for it.
Its been the same way with the other 24/7 series' and is the same with their NFL hard Knocks
It's only 4 episodes, they can't feature everyone. They decide to focus on a select few, and leave the others in the background.
I'd rather a mix bag look at more guys than just one guy. I get if you land on a personality like Bryz which makes for great TV but otherwise, I'd rather watch more locker room stuff or mic'd up conversations on the ice than watch that kind of segment with Lupul. Maybe it's just my preference but I see a lot more substance in seeing a guy interact with his wife and children or a guy going home and recreating childhood memories with his families or watching a guy visit his family when he's in town playing a road game against his favourite team as a child rather than watch a guy shopping in NYC. I get how the whole set up works, doesn't mean that I have to like everything about it.