The density of these offices in downtown Seattle is super high and it's also an area that has a lot of crime so this implementation makes sense. Probably low ROI in other areas like your neighborhood that don't fit this profile.
Except in this study they were comparing writing on a paper to writing on a tablet so it seems that somehow the fact that the writing happened to a piece of paper makes our memory better and its not just the act of writing itself.
I think the "other" in the Wikipedia articles refers to that the six listed (Andrew Viterbi, Franklin Antonio, Adelia Coffman, Andrew Cohen, Klein Gilhousen, and Harvey White) are in addition to the "leader" Irwin Jacobs, not that they are in addition to seven unlisted founders.