Why does Andy Reid encourage Chiefs players to show their personalities?

Andy Reid said that Travis Kelce "has a little zest to him" (maybe referring to this), which brought on a question about why Reid says he wants his players personalities to show.

"I ask them a lot to let their personalities show," Reid said, via quotes from the Chiefs. "You can't play this without doing that, right? It's an emotional game. If you're trying to be something you're not, you have a problem and there's a problem, you're not going to get the full genius or whatever person it is.

"These guys are the best in the world at what they do and they've all got personalities, and they're all different and don't try to hide it. Let it play out, unless it's going to cost the team penalties, let it play out."

I read "let their personalities show" and immediately think of the touchdown dances, which are awesome. Football should be fun so I like it when you can tell that players are having fun.