In football a "hail mary play" is an act of desperation. With no other options available, the carrier throws the ball as far as he can up into the air and down the field in the hopes and prayers that another team-mate will get underneath and catch it. Its called a "hail mary" play because completing it is more or less an act of god.
I've said for a long time that "going f2p" on a game that was designed and executed based on a subscription model is the "hail mary" play of the MMORPG industry. It is good to generate some momentary noise and excitement, but ultimately its a shot in the dark with a slim chance of being a game changer. Its throwing away the ball you have in your hand because you know it wont save you in the hopes and prayers that someone down field will catch it and save the day.
A hail mary play on rare occasion saves the game, but usually its just a more spectacular way of losing. And this is just as true in the field of F2P conversions as it is in the field of football.
In particular, NCSoft totally failed to get a receiver under the ball for their game City of Heroes.
And now the game is over.