closing down (killing) a self running, profit-generating, sustainable business (even if its MVP) that customers love and recurringly use is a good moral decision?
Whenever I have the same question as you, I stop and remember that a lot of people use "ethics" and "morality" interchangeably. If it doesn't make much sense with one word, try the other. :)
Do you think it's a good moral decision to continue taking your customers' money for something you will never improve much at all, because your heart's just not in it? I certainly don't think so.