His name carries about as much weight as Bob Backlund's did in 1993, so it's fine for him to drop by every once in a while, but no one wants to see too much of him. He's still a believable opponent for most of today's main eventers, but not to the extent you would ever think he'd win the title, let alone get any serious support behind him.
Besides, Punk made him look like a straight up dork last time they exchanged words on air and Nash's out-dated schtick sticks out like a jack rabbit's ass. I think he was just there to help keep Triple H fresh leading into his rematch with Taker. It was relatively easy money for Nash, which Nash likes, and nothing too committal.