I've made this exact same question to a friend releasing a record last year.. why spend money on the studio when there wont be any sales?
Roger Daltrey: There's no music industry anymore, why would we make an album? - News - Classic Rock
The way I see it is right now Bands /Musicians release Albums just for an "excuse to have something new to Tour", but what about the old bands? They have more than enough material to keep touring until retirement, so why keep releasing new Music as a Record or Full Album?
Sure some of us still buy CD's, more as an habit than anything else, I always rip them because its easier to carry them around whenever I go and I only buy them because I don't pay for mp3's (Itunes).
But... yes there real a reason to keep making 8-12 songs Albums that large majority of people wont even listen fully (latest DT anyone..ZzZzZzZz), not even mentioning buying them.