ASF Model: contributors become committers. Committers can get elected to PMC, which then gives them a vote in governance over releases and future committers on that project. I.e. a project that includes new contributors in actual governance. "Maintainers" is an overloaded word, for sure.
And yes: nonprofits can be evil just like for-profits; however it tends in some ways to be harder, since they're not exposed to as many "chase the money" ideas as for-profit usually is.