In my estimation, the most likely reason for a stalled out project is accessibility. I knew going into this that the vast majority of the build would need to be at my home if I was ever going to complete the project in my lifetime.
My home is a modest one-story (with a basement) built in 1974. It has a one-car garage that has primarily been used for lawn tools and motorcycles since we bought it, so the garage was too full of other things to be used an aircraft manufacturing space.
That led me to the realization that I had two choices:
build a new garage/shop -or-
clean out my existing garage and put the stuff somewhere else
The first option would have been my preference, but knowing that would be a really expensive endeavor (probably more than the completed airplane), I started considering the second option.
The Sonex kit is supposedly small enough to complete in a one-car garage, with the wings being installed during final assembly at an airport, so I opted to buy a pre-fabricated, 8' x 12' shed kit to put in the backyard - a place where I could move the clutter from my garage.