Thinking about it over the last couple of days, I'm guessing that the last death of someone associated with rock, allowing as broad a definition as you wish, that will have had a great effect on me will turn out to be that of Don Van Vliet in 2010. Richie Havens in 2013 was also very sad but his music, as much as I enjoyed it, made a less lasting impression.
The recent run of passings, beginning with Lemmy and concluding (thus far) with David Bowie, which included the non-rockish figures of Paul Bley and Pierre Boulez, left me largely unmoved or, I should say, no more or less moved than my feelings for the 40 Iranians killed as a result of a suicide bombing mission on the same day as Bowie's death, the reporting of which on BBC America news had to wait until 15 minutes of Bowie coverage and commentary had ended. Because, you know, they're just Iranians. Of course, this is all a matter of personal taste and history but it was interesting to me that those rock musicians who had a very strong effect on me as a youngster seem to have pretty much disappeared. I could be missing someone, but thinking on it, the list of persons aged, say, 60 or more that I care about at all was pretty thinly populated. Eno? Sure, for his early work (including especially the pop albums) but if he's released anything since about 1980 that I go back to at all, I can't think of it. Robert Wyatt? Again, I appreciate and admire him enough, though not nearly as much as many. Actually, thinking of him and his tenure in Soft Machine (a very influential band on yours truly while in high school) caused me to look up Mike Ratledge a) to see if he was still alive and b) to learn what, if anything, he'd been up to recently; he is and the results weren't so encouraging. The Roche sisters? Sure, for the first album--that remains meaningful enough that I'd be a bit sad were one or more of them to pass. John Cale? Ginger Baker? Dylan and Joni Mitchell have been brought up recently and while the former's "Highway 61 Revisited" and the latter's "Blue" were each important recordings for my teenage self, it's been so long since I cared at all about their music that I think I'd just tip my cap and move on.
Even though I've also only listened to portions of their work over the past 15-20 years, I'll be far, far more greatly moved by the deaths of Cecil Taylor, Roscoe Mitchell, Anthony Braxton, Joseph Jarman and others. They mattered so much more to me than any rock musician, no comparison. Again, just personal history and I don't mean to be snippish, but part of me was a bit ticked when (hardly unexpectedly) Bowie's death received massively greater coverage than, say, that of Ornette Coleman last year. To be expected in the major media, of course, a bit more disappointing to see similar proportions in my fb feed.
Old fart gripe over.