I also think that these rewrites are throwing the baby out with the bathwater. Especially in projects related to code quality and analysis, things like widespread adoption and issues going back almost a decade are much more important than raw performance.
For every aspect of functionality, there is a heavy baggage of quirks, bugs, edge cases etc. I am not convinced that a rewrite of a tool that is still in development and still limited to a subset of functionality is able to capture nearly a decade of community work.