I've worked in the technology sector myself and have managed many software upgrades and new software implementations. My best guess is that Garmin's infrastructure is very old and that they use out-of-date platforms. Instead of building something completely new from scratch, they have build layer on layer, without addressing existing issues. This makes platforms almost impossible to upgrade and support. It takes a huge investment to build something completely new from scratch though.
But that's only my best GUESS. :cool:
I feel sorry for the developers and support staff that have to work with this platform.