When I said in 2006 "In the future all games will be online" I got criticized by a lot of senior devs still working on pure retail games. Today of course it seems obvious this is the case. Even triple AAA games designed to be "single player" have online modes, online accounts, post launch add ons via online, online trophies and more to ensure a higher engagement and online copy protection.
The primary reason why online works so well is you can update the game frequently and further retain your players and fans. This can be done in a way that your game virtually never dies. Many MMO's from the 90's are still alive and despite their ancient technology they are still being played.
So this isn't bad news here:
This is good news as it proves how long these games can live. Nearly two decades. Think about it. For a developer having such a title in your portfolio means you have a revenue stream which can take you through years which shake us up badly - like 2016 where many devs were being closed.
Games like Destiny will live until the console cycle ends. And that is a fps. RPG's of course were the first movers but most genres will or have already moved into the persistent universe.
The problem? If too many players are bound to their online games they won't buy as many games as before. So the industry need to rely on growth instead of reselling titles to existing player bases. But this only lasts so long - until they are overfed like it happens this year.
The lesson? You need to design your game to last. The rules you need to apply are hard to learn and to grasp but have been laid out decades ago by people like Raph Koster or Rich Vogel. Google them, read all their talks. They are well worth it.
And if you need help - ask me. I am consulting in this space since 10 years.