I think that's probably what it is, but also when you admire someone so much in your formative years that they become a 'hero', you get some sort of personal connection with them even though you've never met. Like they become a subconscious father figure.
I haven't felt as saddened by the death of someone I didn't know personally since the passing of John Peel, and before that Joe Strummer, both personal heroes for me, just like our Gerry was.