The problem is, we don't know. I've seen PRs that could be curious students, or it could be a first try to see if we are paying attention. It's really easy these days to produce a halfway decent looking PR for someone in their first year of uni and my worry is that an increased volume of low to medium quality contributions will lead to maintainer fatigue. Depending on the project, that may be the point where pressure can be applied to share maintainership.