The missing part here is that on a student/work visa, you're entitled to remain in the country longer than your visa is valid for. When I was living in the US,

The missing part here is that on a student/work visa, you're entitled to remain in the country longer than your visa is valid for. When I was living in the US, I was on an E-3 visa and my wife was on an F-1. My visa lasted for 2 years, however my I-94 (which permits me to remain in the US) lasted for 3. My wife's visa was for a single year but her I-94 was for the entire duration of her study. What this means in practice is that if you travel internationally during the period in which you have a valid I-94 but no valid visa, you have to renew. However if you _don't_ travel and just stay in the US, you don't have to bother. I can't imagine how this is anything but a bug. The US wants my wife to demonstrate intent to return home (e.g. by frequently visiting) but actively discourages her from doing so (by forcing a burdensome visa renewal each time).