He blew in LeBron's ear. So what? He had a pretty good series, and his coach had him guard LeBron, rather than use Paul George, a player widely considered a top-5 perimeter defender.
1. The Jazz rarely have the opportunity to sign quality/talented free agents at a discount price. The Jazz lack talent, Lance has talent and may be available at a decent (movable) price. If this team is ever going to truly contend again, they'll have to take some risks. I think this is the sort of risk they should be taking.
2. Here's the list of non-point guards who played 1000+ minutes and averaged at least 0.4 assists for every field goal attempt this past season:
Joakim Noah
Nic Batum
Tyreke Evans
Lance Stephenson
Josh McRoberts
Manu Ginobili
Andre Iguodala
Gerald Wallace
Nick Collison
Dude's not a chucker. Even on an offensively challenged team, he was fairly selective.