Beyond any implicit insult, I don't like the logical fallacy upon which "too much time on his hands" is founded.

There's no way for an outside observer to know how much free time someone has based only on a viewing of the fruits of their hobby. That guy who built an ornate castle out of clothes pins may well have a packed schedule, and it was all he could do to cram the building in a few hours a week.

Actually, remember the guy who built a fully-functioning Daft Punk helmet that was making the rounds a couple of weeks ago? That took him 18 months. It was a labor of love for no external gain, but he quite likely had very little free time for it to take him that long.