As someone who hasn't looked at the repositories in question;

> why don't you submit some PRs to help them improve?

Is often a non-starter. If you believe a codebase is poor quality, any changes to improve it have a strong risk of making it worse and/or wasting your own time. In the case that you aren't a key player in said codebase already, it is even more likely your attempts to make changes will fail. Its not impossible to improve these repositories however doing so is quite a different skill-set to identifying their failings.