The fact that scientists have to be "always on" these days is an interesting development. Its probably largely down to the fact that the academic job market is so terrible that only those who are fanatically dedicated can succeed.
In some ways, this is a good thing for science: only those who are truly dedicated (and thus likely very good at it) will become professional scientists. On the other hand, the poor academic job market also means that its tempting for smart people interested in science (who could be very good at it) are likely to go and do other, more lucrative activities (e.g. software, finance, etc.)
Yup, this typically does not work out well. I love science, and in an ideal world would work at it for the rest of my life. However, there's no freedom left in it. You have to go raise money, work on what other people want you to, and put up with most of the private sector crap while not being adequately compensated for your efforts.
When I was a researcher, everyone I knew worked all weekends and evenings. What did they get from this - not much. In the private sector, there's a lot of crap but at least they don't expect you to be fanatically devoted to your job.
The worst part is that academia has little to no security left, and that was always the tradeoff - less money but more security and freedom. I don't actually see how this is going to continue, and these issues will retard science until the funding models and expectations change.
In some ways, this is a good thing for science: only those who are truly dedicated (and thus likely very good at it) will become professional scientists. On the other hand, the poor academic job market also means that its tempting for smart people interested in science (who could be very good at it) are likely to go and do other, more lucrative activities (e.g. software, finance, etc.)