Greetings!
Lately there have been several people/Lalafell/creatures worried about ARR's launch failing. As such, I thought I would provide several reasons why you shouldn't hide your kids, hide your wife, and hide your husband too because FF14: ARR isn't going to fail and go F2P.
1) SE Used Their Own Funding
SE used in-house funding to rebuild ARR. As such, they don't need to answer to investors. Several, but not all, of the MMOs that made the F2P transition had to go F2P because investors wanted an immediate return on their failing investment. SE doesn't need to do this at all, or they would have gone F2P by now.
2) Yoshi-P Takes Player Feedback Seriously
If there's one thing I absolutely love about Yoshi-P's team, it's that they actually listen to the players and take feedback seriously. All one has to do is take a look at the road-map to see that they plan on making changes based on feedback, thus making the game even better.
Many of the MMO's that went F2P didn't take player feedback seriously (1.0 dev team did this too!), which is why they failed and went F2P.
3) Yoshi-P
This guy is just O-MAZING. Forget amazing, we're going with O-MAZING. If anyone can make this game succeed when it's 4th down & 50, it's Yoshi-P.
4) Console Playability
No other MMO's allow cross-play between consoles and PC's. Sure they "might" offer a PC & console version of the game, but PC & console players can't play together.
Not everyone has a Behemoth (Or as I prefer.. a Pighemoth ) of a PC able to run today's MMO's. Being able to play a QUALITY MMO with everyone on a console allows Square Enix to tap into a HUGE market-share of gamers. In all of the articles I've read about the failure/success of MMO's, none of them mention the console market-share of gamers.
TL;DR FF14:ARR WON'T FAIL!