Out-of-state students on F1 visa (be graduate or undergraduate) generally have to abide by certain academic requirements to maintain legal stay.
Historically, for the graduate student subset, a course load of 6 credit hours has always been the minimum requirement for face2face lectures in any particular semester. Under very specific circumstances (read: literally one course to graduation or similar) will the DSOs of their school mention the case on their SEVIS records and allow them to continue. Arguments can be made against the morality of not allowing students with improper internet access to come in. But don't let armchair experts lead you to believe it wasn't always this way. Because it was.