Dioramas, Dioramas, Dioramas...
And also gaming... And just how great they look lined up.
OK, that's a few reasons I guess, but basically I have an love for the military aspect of the films, and lean towards that in my collecting then I suppose. Star Wars is a rich fictional military background... It's something that is expressed not only in the films, but in video games, books, the RPG, comics, the Miniatures Battles game, and the action figures.
I like to make a permanent diorama from time to time, but I also like the idea of the ability to flesh a diorama out "on the fly", just making it up as I go... Maybe utilizing the weather, or a natural outdoor setting like a small creek at just the right time. A lot of good army builders are fun for that.
When I was a kid, army building was fun with the G.I. Joe line because you could have some kickass playing around when you had a small army of Vipers, or Cobra Soldiers to fight your heroes in the Joe line... Flint always kicked some rear as I recall (Decked out in Han's trenchcoat of course).
I think a lot of folks just like the looks of a lineup of Rebels, or Imperials... Customizers take it another step by making some diversity in the ranks for realism, but either way it's an additional way to own a bit of Star Wars... And own it over and over and over in some cases. My stormie army is over 100 now, and they look great together.
I'm just antsy for Hasbro to crank out some good army builders for figures that haven't had a really good poseable army builder made yet. The Hoth Rebel's probably at the top of that list... I'd put either a new SA Endor Rebel or SA Rebel Fleet Trooper as 2nd for the Rebels. For the Imperials almost ANY figure needs made SA at this point... Snowtroopers, Sandtroopers, Stormtroopers, Biker Scouts, Officers, Death Star Troopers, Gunners... They all could use a SA version I think.
I hope the SA Clone was just the start of something great from Hasbro. So far it's a one-time-only deal it seems, but I have hopes that this figure's instant popularity spawns some other SA, or near SA figures that are just that "perfect".