This would immediately go away if Sony decided to offer free online. Being the dominate console of this gen they can do that and Microsoft would have no choice but to follow.
This is not how business works. You do things like free online in order to attract demand and sales, not in response to your own high demand and sales. PSN was free since launch of PS3 and added new free features every year, and then PS+ was introduced as a huge value, and still the market remained loyal to XBL all throughout last generation.
Big companies last gen proved that gamers are willing to pay for anything that used to be expected from games, from microtransactions of avatar clothing to paying them a fee to connect you to another player on your own internet connection.