As long as the newbie doesn't walk away feeling like they've been shunted into the kindergarten playpen. But so long as you get ahead of that expectation mis-match, it actually is a really good way to get to know both a project and its surrounding development culture.
I'm a student, I don't think it would feel like that at all (as long as the attitude of other team members didn't make it so).
There have been days where I've actively searched for some OSS project that is accessible enough for me to work on - because usually the ideas I have myself are things I'm not capable of! Or I just need to think more about how to get started, and when in this mood I'd rather just get hacking on someone else's project's issue.
My point is, issue triaging could be a great way to learn the ropes of a project (and get to know the team a bit), and you'd probably find yourself occasionally (then gradually more often) thinking "hey, actually I reckon I can have a crack at this myself". That'd be really satisfying for a never-contributed-before fresher.
