This is backed up by the evidence we have from how popular Casascius conis were, and all the other variations which were released after. People just love to hold a physical item, and I'm not sure what the psychology is behind that, but there's definitely a reason for it. Casascius identified this early, and made major profits during the time they were selling the coins.

However, despite us wanting to hold a physical item, modern times are changing quite quickly, most people are becoming accustomed to handling their finances online, where as 5-10 years ago, most people thought of it as insecure.  So, while at the moment people like shiny physical things, it is quickly changing. Several challenging banks are now operating entirely online, and don't even have any local branches that you can go too. Bitcoin will most certainly benefit from this psychological shift in our culture.