Xbox gamers are used to paying money for their Xbox Live subscriptions. If they don't then they're locked out of online multiplayer, as well as services like Netflix.
That was possible before because Sony's PS3 online services were so inferior to Xbox Live, but with the growth of PlayStation Plus that's no longer the case. Sony took a step backward by making PS4 gamers pay for online multiplayer, but other entertainment services on the platform are still free. Microsoft could have taken this opportunity to change its own policy there, but instead it chose to keep charging users for services they're already paying for.