I think you will find its a valid question. We have no shortage of quality submarine games like the Silent Hunter series set in WW2. However there has not been a single modern day submarine title since the 90’s. With the market so heavily occupied by first person shooters and flight simulators why is this one type of game lacking?
The firepower of the submarines is superior to those in WW2 titles. Plus you have the bonus of that cool effect when the subs come out of the water. Then there are the possibilities for mission types with things like having to meet with helicopter’s to transport spies to a destination.
Then there are the bonuses for the company who makes it. You don’t have any competition and sim fans would eat it up. If there are any games developers out there its worth some thought.