Obviously, and understandably, the Internet is awash with words about Syd Barrett and his legacy (which is, not exactly "questionable", that sends entirely the wrong signal, but, how to say this, he seems to be worshipped, and I suspect that's not too strong a word, much more for what he could have done than for what he did - his is a story of real sadness that has been somehow turned into a cult). Jody Rosen on Slate has some worthwhile things to say, and in the Guardian you can choose from Richard Williams, Nick Kent and Rick Moody. The BBC has extracted a few paragraphs from Joe Boyd. I'm sure there is much more that can, and will, be said. So it seems a bit pointless for me to add anything.
Except: I have long harboured an irrational, but genuine, hope that Barrett would one day, J D Salinger-like, emerge from his extended hibernation and present us with new songs that would thrill and beguile us. If Salinger dies, there will be no hope left.