FFXIV is a beautifull naked world with no content right now. The only option you have is ranking up. Which in theory isn't really a problem, because that's what you do at the start of every FF anyway. And with the last update they adjusted Rank 1 - Rank 30 for players just so they could get some more joy out of ranking up.
As a next step however, for people to enjoy ranking up after 30, the party system really has to work. The new way of gaining SP is making people not want to party or fight only one mob type: Coblyns. This is really bad. I'm not worried though. This issue is probably going to be fixed soon.
As for the question if FFXIV Players will return? I want to state the following analogy:
Think of FFXIV as an amazing movie, which you are trying to watch in your webbrowser. It's a great movie but you got this crappy internet connection and you have to wait forever for it to download. Think of "download" as being the progression of the state of FFXIV. Now you got several options and I'm going to pick three simple (nice/ non hater) ones.
1)You can wait a bit and then watch a tiny bit that has been downloaded and repeat.
2)You can wait just long enough to be sure that when you start watching, the rest of the download finishes while you watch.
3)You can wait a long time for it to be downloaded fully and then watch the whole thing.
With this in mind:
Do I think people will return? Yes
Why? Because FFXIV has a strong solid foundation to build upon (even if it's with trail and error).
When do I think will players return? Well it just depends on the fact if players are of type 1,2 or 3.