Why would you not expect it? The Dead weren't wacko anti-America musicians. They were rarely political and would never have pulled Dixie-chicks type of nonsense. I think you were being presumptuous about them.
Sure they had some pet projects, like the rainforests, etc. But no agenda against the country whatsoever...
Jerry was one of the great preservers of American music.
He passed it on.
If you ever are passing by Monroe, Utah, stop in at the hot springs. They are now owned and run by a former Grateful Dead Promo man, who uses the area for hot springs, concerts, and an art shop. He probably has 40 acres where you can park a trailer and camp too. I bought some beautiful blown glass pens and frogs from him a few years back, and he still keeps the place up. It is one of the richest Grateful Dead tribute places I have ever seen. You would like it.
The only time I ever heard political statement from the Band, was during a show at Nassau, when Bobby said, "this ones for Bobby Sands.."
Correct me if I'm wrong, but I believe the same can be said about Jim Morrison and Jimi Hendrix. I know Jimi was anti-communist and not anti-Vietnam, and I think I've read that Morrison was the same way. The surviving Doors have made political statements recently, though.