> To save money.

If they want to save money, hostels are usually half the price of hotels. Why would they even choose a hotel in the first place?

Plus, my experience is that hotels will simply cancel your booking, or force you to upgrade, if multiple people turn up to check in for a single room. They don't need some passive-aggressive doorless bathroom, they have the right to tell you to book a 2-person room (whether twin or double bed) for 2 people.