That's what I figure it is, just take a look at the filabot [1]. It's taken in far far longer than anticipated but he's still keeping at it, just sent another update today. I would be very surprised if this wasn't the cause of most of it, with another big cause being the ones that end up getting far more attention than expected, needing to ramp up manufacturing to a level they didn't even consider possible (i.e. printrbot [2]) at the time.

[1] http://www.kickstarter.com/projects/rocknail/filabot-plastic... [2] http://www.kickstarter.com/projects/printrbot/printrbot-your...