There's no certainty it will be justified. Just an educated guess.
Say you've been working on a game for 3 years. And you think it will take 1 more year to complete. Now, you can throw away those 3 years of development, and scrap it and all that money was wasted.
But in this case lets say they opt for another year so the development is 4 years into development. Now once again it's not complete they think it will only take 1 more year, only it's more certain this time. Do you throw away 4 years of development, or work on it another year and complete it?
Imo, as long as the game has a shot to sell and make up for the expenses almost for certain of the 5th year. They should do it. with hopes it pays for the whole project or more. And thus the project becomes a five year dev cycle.
my point is hindsight is always 20/20. and there's no way of knowing for certain whether or not the product is justified or not. Until after the project is released.
