Never a bad move to play with a team like the Spurs, and the money is always good in the NBA.
With guys like Ginobli getting older may even be a few minutes for him at some point.
At worse he has a NBA contract, earns awesome money - way more than most will ever earn, and a front row seat to some great basketball and is involved in one of the best clubs, coaches, team mates in the world.
Best case he gets a bit more playing time and gets a bigger contract next year, somewhere in the league.
Its a cant lose situation imo, i would have done the same, the Spurs are the type of club you would try to stay with as long as possible, obviously if there is a great offer to play more and earn more then you look at it, but im not sure Patty would have had too many other guaranteed offers on the table.