A dorm usually isn't a legal residence. For example, most states don't allow you to get an ID with a dorm address. Credit cards and bank accounts usually can't issued with a dorm address. Voting, jury duty, etc. would all be based on your permanent (typically parent's) residence.
I think that is the where the poster is coming from.
So the question becomes, how does Netflix plan to define a household, when many people might not be at their legal residence for much of the year? And how will Netflix enforce this? Will they geo-lock service to a subscribers billing address?
Will business travelers who spend 5 days a week in a hotel not be able to use Netflix outside their home? Will students at boarding schools not be able to use Netflix? etc etc etc
Personally, the main advantage of streaming for me, is to be able to stream content anywhere I am. On a train, waiting for my carpool group to get off work, when traveling for work, etc.