There is nothing wrong with trying different things. But the fundamental problem here is that projects and their communities are social projects and need to be to fulfill their purposes and to ensure long term maintenance. In a free software context, rewrites just like forks (1) are fundamentally an asocial (2) activity because they fragment the community (if successful) and then increase overall maintenance burden if not able to replace the original project completely (rarely the case). Disrespect the license choice of the original authors makes this worse.

1) There may be situation were are fork makes sense (e.g. because one project can not serve different use cases well): 2) Which is why usually a "higher goal" is used to justify this, e.g. authors pretend (or lie to themselves, or may be be stupid enough to actually believe this) that some improvement in memory safety is really that important.