I believe this creates a constant "attachment" to work, and does not allow you to detach. Especially on holidays you should be able to detach and be able to forget work for a few weeks. (Besides: It also serves as a good practice to the workplace: What if this person is not here anymore due to illness/finding a different employer.
As for me, I always to keep work at work. I don't work weekends, and I never work on holiday. I am a software developer, and do keep on date on aspects regarding software development. But this is because I want to, and often involves subjects which are not relevant to my work (I developer ASP.NET web applications, but privately I like to do stuff with assembly and C++, or fiddle with an Arduino or Raspberry pi)