I build exclusively in 1/72 scale; both aircraft and armor! In my opinion, it's God's own scale; or as one other friend calls it: the One True Scale.
I could also say: Welcome to the Dark Scale, we have cookies!
I started out building exclusively 1/72 scale because I loved having consistency in my collection. It was also easier to see the relative sizes of every aircraft (and vehicle) to every other aircraft and vehicle. Then there is the same reasons Fermis gave which to me is just cream on the cupcake.
So, have fun and savor the moments of building every new 1/72 scale jet!