Releasing an international version and several U.S. versions segments the market, slowing down 3rd party ROM development particularly for the U.S. versions. Carrier ROMs are bloated, non-standard android environments, and lag behind the latest version. That situation is unacceptable; no new Samsung Galaxy phones for me.
Presumably lack of demand.
"slowing down 3rd party ROM development particularly for the U.S. versions"
Not Samsung's problem.
"Carrier ROMs are bloated, non-standard android environments, and lag behind the latest version."
And there's a distinct class of devices that run stock Android. And in all likelihood this class will continue to be outsold by an order of magnitude by this device and its non-standard carrier ROM that lags behind the latest version.
"That situation is unacceptable"
To a tiny minority.