there's just one thing?
Why is it that most people haven't even heard of this film before? why is spot motion so neglected?
** Because most stop-motion films have had horrible stories and weak characterization. Most have been box-office failures and mediocre films forgotten over time. ** Stop-motion is also the most physically labor-intensive form of animation there is. Time equals money, and that's one of the big reasons why it's not done so much anymore. Practically everything that can be done in stop-motion can be done with CGI cheaper and a heck of a lot faster.
Before the 1990s, I could count the number of MEMORABLE and GOOD stop-motion features on one finger: Mad Monster Party. Other than that, the only really appealing ones are the Rankin-Bass holiday specials (Rudolph, Santa Claus is Coming to Town, Frosty in July, and Jack Frost) but those are all TV specials.
Even after the 1990s, there's really only one other good stop-motion film -- The Nightmare Before Christmas which is by far the best one I've seen. The tremendous box-office failure of the follow-ups to Nightmare (James and the Giant Peach, MonkeyBone) ensured that there were no new stop-motion animated films in the United States for YEARS besides short sequences in films like Elf.
The other thing about stop-motion is that CGI has gotten so good that it can fake the look of stop-motion fairly well. Sure, some commercials still use stop-motion but not 1/10 as much as they did just 10 years ago.
A few other things not mentioned about stop-motion --
A) Unless you have really good animators and nice equipment, it tends to have a jerkiness to it that's really off-putting to many people. I can't remember the number of special effects sequences I've seen in films that come off looking fake because of that aspect of stop-motion.
Even several of the films I like very much have horribly fake-looking stop-motion segments in them such as the Tauntauns in The Empire Strikes Back, the Rancor Pit monster in Return of the Jedi, and just about anything done with stop-motion in Clash of the Titans, the original King Kong, and a host of Harryhausen movies.
B) It's very labor intensive. You have to build EVERYTHING by hand unless you do a lot of CGI and computer compositing. For example, even the shortest George Pal Puppetoon were complicated productions. He insisted on the characters having lively expression. The problem is that EVERY expression had to be carved IN WOOD. If you have character that emotes 50 different ways, you're going to have probably at least 100-150 different replacement heads for the puppet! That's not counting all the IN-BETWEEN "muscle twitching" replacement heads to go from one expression to another.
The reason why Nightmare and Corpse Bride look so smooth is because in addition to having really dedicated animation crews working on those films -- these guys LIVE and BREATHE stop-motion --, those films have the advantage of technology that wasn't available to Harryhausen and George Pal.
They use instant-playback digital camera systems that allow the animators to go back as many frames as they want to see how to position the stop-motion characters for succeeding shots to make the animation as smooth as possible. Before, they had only the animator's judgment and calipers to see how far to move characters. Without instant playback, even the best stop-motion guy is going to make some mistakes. Some guys are remarkably good WITHOUT things like the instant-playback systems, but by and large most larger stop-motion productions use those digital cameras now.
The other advantage are the computers they have today. Besides enabling instantaneous footage playback, they can probably splice in footage or digitally create new CGI animation so good that you can hardly tell the difference between a stop-motion shot and a CGI shot. I would think that with Corpse Bride they're mainly using CGI to create special effects that would be very hard to animate by hand and to enhance the backgrounds if not create backgrounds that would be very difficult to build by hand...
The only reason why The Corpse Bride got made is because in spite of all his commercial failures Tim Burton still has a cult of mystique about him in Hollywood and can call the shots on just about anything he wants to make. There's no way this film would have been made, let alone in stop-motion, PERIOD, without Tim Burton's say-so. Most producers and executives in Hollywood are convinced computer animation can replace ALL forms of traditional animation even when CGI looks half-assed and really doesn't suit every circumstance.