I didn’t know I had to answer the question since I am doing neither.You still didn't answer the question. Why not make a new game with the same concept instead of trying to continue someone else's work?
For the sake of argument, if someone was building a house and then stopped it would make sense to start from where they stopped, particularly if you really liked how they designed their base of the house.
I suppose a more apt analogy would be that you are copying their design. One reason for this, beyond the fact that you really like that base design, would be that you would be less likely wasting funds because you already know exactly what is needed. This may not be a problem for a large construction company but if you building as a solo project, you may not have everything exactly planned out and/or have limited funds thus less ability to overcome waste.
My real question that I would want you to answer is why is this such an important issue for you? You have been arguing for pages now, trading insults back and forth.
From what I can see, you are not the owner of the original game which is who I would expect to have copyright issues from if any were to come up. You may even be right with your opinion. I neither know nor care. Frankly, I have skipped over most of the argument because I find it tedious.