That's partially true. But more importantly, when a manufacturer like Samsung meets with a major carrier to show off their latest line of devices, the carrier will invariably come back with a list of demands and changes that they'll need to see before they'll agree to carry the devices.
In order to respond quickly to the carrier's requests, a manufacturer needs their own custom platform and code base to work from, and that's why each manufacturer has their own custom Android UI platform to work with. It's a situation RIM played very well back in 2006/2007/2008, where they not only controlled the software platform top to bottom, they provided a surprisingly flexible theme engine to allow each carrier to quickly design their own custom home screen UI; some quite beautiful (especially from some of the European and UK carriers), others not so much, but all radically different from one another.
Apple completely changed the game by creating a device that average users would gladly dump their carriers for, and that alone takes away most of the power from the carriers. Today I think Apple, Microsoft, and even RIM are pushing to change users' expectations about how much control the carrier should have over their cell phone software. But the old guard manufacturers like Samsung and LG have been amazingly successful playing the cell phone industry by the traditional rules, so I think we as consumers still have a long, long way to go before we'll see any real change from the carriers or old school phone manufacturers.
In order to respond quickly to the carrier's requests, a manufacturer needs their own custom platform and code base to work from, and that's why each manufacturer has their own custom Android UI platform to work with. It's a situation RIM played very well back in 2006/2007/2008, where they not only controlled the software platform top to bottom, they provided a surprisingly flexible theme engine to allow each carrier to quickly design their own custom home screen UI; some quite beautiful (especially from some of the European and UK carriers), others not so much, but all radically different from one another.
Apple completely changed the game by creating a device that average users would gladly dump their carriers for, and that alone takes away most of the power from the carriers. Today I think Apple, Microsoft, and even RIM are pushing to change users' expectations about how much control the carrier should have over their cell phone software. But the old guard manufacturers like Samsung and LG have been amazingly successful playing the cell phone industry by the traditional rules, so I think we as consumers still have a long, long way to go before we'll see any real change from the carriers or old school phone manufacturers.