My dad worked in construction, and from the late 80's and throughout all of the 90's his company kept offering him a company phone (I think car-phone first).
He never got one, because as he said, if they have your number they'll call you, if they don't then they'll solve their own problem. Looking back on it now, it was prescient advice.
I don't really agree... I like the flexibility. Sometimes someone from the US calls me with an urgent problem in the evening (I'm in Europe so not much overlap in work hours).
So what... Sometimes I go to the shop or bank during the day. Or even a walk to the beach if it's not so busy. They're paying me to do a (global) job, not to sit at my desk between 9:00 and 17:00.
Personally I love this flexibility. And I don't feel like I work more than 40 hours, I don't even count them but I doubt I do, especially if I omit the time I spend during "working hours" reading hacker news or other stuff. My work is my hobby anyway.
I do think people who like having fixed work times should have the opportunity to have them. But I also think people like me should be able to work like this without it being considered a bad thing.