This was probably Dave's first publicity photo and it was used in Sounds for an article entitled "Dave's Magic Leads To Oblivion". Too bloody true mate!
The reason for the terrible quality is that it is a photocopy of the Sounds article. This photocopy was then used in a mailout to try and get gigs (no such thing as desktop publishing in those days).
Amazingly, not one gig was forthcoming from about 150 of these luxurious leaflets. Dave promptly sank back into oblivion, where he has stayed ever since!