Wayfarer
It's hard to believe there's anyone above the age of 30 who doesn't know who Trower is.
I think 50 might be a more reasonable cutoff for that.
Bridge of Sighs was a gold album. I can think of at least six different songs from it that still get plenty of airplay to this day. The RRHOF isn't for recent acts. I wouldn't expect gen-x'ers to have any idea who the majority of the people in it are.
That's funny because I haven't heard Robin Trower on the radio in years. Granted, he was on the air a lot in the time when there were no such thing as "classic rock" stations, just rock stations, but I really haven't heard much of his stuff since then.
Now I will definitely agree with you that Bobby Darin is an odd choice, as he never was associated with Rock & Roll as a performer, and I don't see him as much of an influence.