Interesting thread. It never once occurred to me to worry about insurance on my bicycles. That's probably because the most I've ever spent on a bike was around $900. Hardly worth insuring something of that value that's pretty unlikely to be stolen from my garage.
Now, if I had $7k worth of bikes, where any one of them was in the couple grand range of value, I'd probably think about it. I wouldn't remotely bother for a couple of $600 bikes. But good thread and useful info here.