Well, let's not commit the mistake of thinking this is due to laziness and incompetence. It's an unfortunate business decision, where the cost/benefit of modern games prohibits extensive support to any but the most successful games these days (and I mean in general, not just ubisoft).
And since SHV did not do very well on launch (as far as I know), I am not surprised that support has been terminated.
THAT SAID, the fact of the matter is that SHV is still an enjoyable game, and the first patch does fix outstanding issues.
Of course, to really enjoy it you need to load some mods (the GUI mods especially), but once you've taken the time to do so, you can have a brilliant experience. I absolutely love its design as a "captain simulator", and find it extremely immersive.
Indeed, with the gramophone mod I'm using (tons of extra songs, don't recall which one it was), I frequently will just pop in the game as the sub is sailining somewhere, lie down on the captain's cot, and read a book while listening to the gramophone.
Itkovian