What's the point for $50m Gil to do the Cloud beta test if you can't keep it?

[NekoMataMata]

I thought at first you got to keep the 50 mil but then read and found out you didn't. What's the point of helping out with the testing for no rewards and loosing precious playtime.

Oh, I don't know, maybe so that you can tell them if the cloud servers are a good idea or not since if they work well enough then you'll benefit from being able to play them in the long run?

The gil is literally there for the purpose of enabling you to do whatever you need to do to test out the servers. That's it. It's that simple.