This was from an interview a few years back. It could have been because he wasn't making any money from it. I haven't kept up, but glad he's embraced it.
Astley participated in a rickrolling himself, at the Macy's Thanksgiving parade a few years ago. He popped out of a float in the middle of another musical performance and started singing Never Gonna Give You Up. It was a staged stunt, with a canned background track ready to go, and the TV announcers obviously feigning surprise.
Where'd you get that impression? He's been pretty cool about the whole thing last I heard.