Ok, so from a business perspective, I think this is a smart move by LA for two reasons.
1. It solidifies their PG position for 3 years to come. While Nash does lack on the defensive end, he hell of a lot makes up for it on the offensive end. Furthermore, it's also evident not many players can stop the most elite PGs when they enforce their will. It takes team defense rather than one on one.
2. The draft picks LA gave up imo have two sides to it. One side, no development of youth. On the other hand, their draft picks would not be worthy enough to get high prospects for a team that's window is steadily closing.
As far as my competitive side goes. I'm disappointed in Nash for having the Lakers as a team on his list. The Knicks I could understand, but this doesn't make sense to me at all. I guess at his point of the career, he wants to win one bad. Though you figure he could have just gone to Miami or OKC.