Same is true for singleplayer only games. Doesn't mean they don't play it though, in fact I'd take that to mean they think the singleplayer isn't good enough to be worth finishing not that they don't want to play singleplayer.
Not really, in 2008-2009 we had Activision posting that the majority of the people back then did not finish the COD singleplayer and their was a large percentage not even start the story. Their were literally millions of people spending hundred of hours into a game but then not even played a minute in singleplayer. In that time people still cared about the singleplayer and games like World at War certainly not had a bad singelplayer. After that came another huge outcry when popular sp games were getting multiplayer (cutting dev time for singleplayer) like Uncharted 2 or even worse like Dragon Quest online the worst nightmare coming true...