We have windows because glass used to be very expensive. Shutters allowed us to use smaller sheets, with the added bonus that if one of them broke, you could just replace part of the window.
Today, large sheets of glass are much cheaper, and many windows feature faux glass panels – a process that uses a large sheet with interlocking moldings. Of course, it costs more to create than a simple window. We are paying too much to replicate the effect we originally set up to save money.
If you look around you will realize that we make choices like this all the time when new technologies appear. Cruft is comfort.