To be honest, it depends on how responsible a student is. I myself is a still a student who relies in Bitcoin to help me finance myself but I for once haven't forgot about my studies and had an average grade of B+. You should consult your students and approach them to give them some advice. It's not Bitcoin's fault but it was students entirely. 
I agree because same thing applies to me that Bitcoin does not become a hindrance for me to continue studying because I equally manage my time in working into earning Bitcoin as well as studying at school. I do planning to keep myself aware that I am not just earning for finance but also learning for my future. It depends upon the student if he will just focus and be greedy on what Bitcoin can provide or still persevere on studying while doing crypto works in exchange of earning Bitcoin and other types of cryptocurrency coins. Students out there must be aware that it is their own responsibility to stick into studying for their own good and not pushing it through that Bitcoin plays as a hindrance in focusing into their studies because it was not reasonable at all.