I don't think that development is that important. Many coins are putting "fancy" and pretty much useless features instead focusing on the most important part of the "game" - adoption. Currently 95% of them are like a girl who is putting makeup in front of the mirror, but she's not going out of her home.
If the bolded part is true, then the second part doesn't matter, because you might as well just be developing a Bitcoin app instead of designing a cryptosystem. There are coins working on fixing fungibility, scalability and privacy. If it were easy, Bitcoin (or anyone else for that matter) would have already done it.
The bolded part is true. Let use not forget it says
coins.