He got a lot of contributors because those contributors wanted to participate in a rewrite. I.e. the opportunity to "move fast and break things". Not exactly the kind of contributions you should be looking for in a package manager that so many of us rely on.

If he was asking for C/C++ contributors, he'd be asking for help maintaining a mature project. That's less fun. It mature, grown-up work for serious people. Those serious people probably already have serious jobs. So, fewer people will show up.