It's hard for small developers who make useful things to get noticed on GitHub. The only hope is to get retweeted by some established user. This seems silly, we need better ways of making sure people can find/discover good software.
So it's hard to spotlight anonymous devs on their own, because you can't establish trust with someone who isn't known for anything yet.
Closed source seems to require more trust to me.
I think trust is very difficult to manage and do some checking of owners of PPAs before using them -- containerisation can help, but doesn't prevent information gathering and other trust-breaking activities (backdoors, etc.).
Although they've added plenty of trendy social network-y features that's what it is as its core.
There's no silver bullet for "getting noticed" whether on Github or outside of Github.