I think it depends a lot on the kind of repos.
While it shows that you like to use source control, I'd probably ask myself why spend time on versioning me playing around with a new programming language at all. Not really a minus in my opinion but it does make it a bit harder to find the interesting repos though.
Simple university assignments
Especially if it's the "implement algorithm XYZ" type assignment where you'd just use a stdlib function in any real-world application I consider those pretty useless/irrelevant when looking at someone's GitHub profile.
However, chances are good that the code of such an assignment is not very good. You probably didn't like doing it in the first place and just wanted to get it done, without caring much about code quality. I get it, I probably did the same back then. But I just submitted that code to the professor and did not publish it on GitHub.
If the majority of your code on GitHub is "bad", chances are good that people will get a bad impression from that code first and maybe not even notice the good code. This is especially important since you cannot directly control which repos show up on top in your profile. If there's something you don't want to show up immediately I don't think there's much you can do besides making it private (if you can) or deleting it.
So my recommendation is to make sure people **see recent and good code first ** when going to your profile. If you are actively contributing to a repo chances are good it shows up on top anyway. For repos containing "bad" code you wrote a long time ago, you could always add a
README.md file mentioning that this were e.g. first attempts with $language or that the repo contains your university assignments. That way people know not to expect your best code in there.