None of those are EV specific, they are just reasons the car market in Europe would be small. Rather than speculate about all the causes I thought I would just look it up:
In 2013, there were 12 million¹ vehicles registered in the EU out of 733 million people. And in the U.S. there were 15 million² sales out of 315 million people.
So it looks like Europe is buying cars at about a third the rate of Americans.
Also, when you look graph ², you can wonder how much of that is due to recession.
(found at random via google search, so I don't know how trustable it is, but seems legit. : http://www.calculatedriskblog.com/2011_12_01_archive.html )
¹ http://en.wikipedia.org/wiki/European_Union
² http://2.bp.blogspot.com/-gzzddTbQ7Mg/TtfoT07ehTI/AAAAAAAALe... (via ³)
³ http://www.calculatedriskblog.com/2011_12_01_archive.html
Nonetheless, your point is still valid, European buy less car per person.