I don't know why all games are slowly developed. Maybe it has to do with the financial crisis, no budget for adding more developers to the team. I also have a feeling that most mmorpg's are not that profitable at all. The whole free to play model may be better than pay 2 play in terms of cash flow, but still not worth the investment.
Most MMORPG's that go into the commercial phase are profitable, the length of time they are profitable depends on a lot of things though. Nowadays the P2P model is dieng and games that are P2P tend to go into an F2P model, and it's definitely a better model, in terms of profit. Most P2P players tend to hate F2P models because of 2 things:
1. They pay more on an F2P game because they don't have a set amount to spend.
2. Games that go F2P in NA are usually published by horrible P2W companies.
I'd say if a company could stop going P2W then F2P is better in every way. However, near a games death, and every game does die, it goes P2W. Luckily for Aeria, that happens pretty late for most of their games, and it's not exactly P2W for a lot of their games because Aeria has a huge player base.
Now with all that answered, this game is probably one of the fastest well developed games out there. Games take a lot of time to develop, so that's why I guess you could say "all games develop slowly". But really they all take an average amount of time.
My guess for when this game will come out is still around April. CBT atleast.