> how would it be different from me renting a movie at home and having friends over?
It would be different because Netflix has a contract to pay money for that licensed content, and sooner or later, that contract will need to be renewed. At that point, a Hollywood exec and a Netflix exec will sit across a boardroom table, and the Hollywood exec will say, "Your offer sounds OK, but we need to stop this watch party thing."
Whether that demand makes sense to your or I or the Netflix exec is moot. The Hollywood exec wants it, and it doesn't matter why, because they get to decide whether Netflix can keep licensing that content.
It would be different because Netflix has a contract to pay money for that licensed content, and sooner or later, that contract will need to be renewed. At that point, a Hollywood exec and a Netflix exec will sit across a boardroom table, and the Hollywood exec will say, "Your offer sounds OK, but we need to stop this watch party thing."
Whether that demand makes sense to your or I or the Netflix exec is moot. The Hollywood exec wants it, and it doesn't matter why, because they get to decide whether Netflix can keep licensing that content.