In this case I think he used so many LED's because space is an issue. He is building a full mock up of an F-16 for a flight simulator. Looks way cool and I would love to have one, but the time and expense is a bit over the top.
This guy has over 1000 hours into the build of his simpit and still isn't done.
http://www.xflight.de/f16/ Supposedly all the buttons work. can't imagine the amount of wiring that went into this. Check out the pictures section!
(site is in english and german - click the appropriate flag to change)
edit: Very detailed reproductions (too time consuming for my lazy @$$).... check out the "original equipment" vs his "repro equipment"
First pic is the original.