It was supposed to be a profitable investment considering you had a large Bitcoin bankroll, and considering freebitco.in was a solid and reputable platform in crypto industry since 2013 or so. That was the main idea. However, things started getting too unstable there and it's not safe to keep BTC deposited at the platform anymore. If the site was safe like before, FUN could remain on the current cheap price, but the investment would be still profitable through BTC interest income for users with large bankrolls.
You're right that holding BTC on the freebitcoin site may not be the best idea now, as the site has become unpredictable lately in terms of security and operability. But the paradox is that there are still big players. At least they periodically appear in leaderboards. Either the site works without any problems for these players, or they just don't want to notice what has happened to the site recently.