I also have locked a part of my FUN tokens for 1 year and with me probably a lot of other users have done the same. You are right that you can not really predict the market but the strength of holding the FUN tokens is the premium membership you get which will give you WOF spins, extra interest, cashback, ...
Because $FUN is a token from a good project which has support from Freebitco.in that is a good gambling site. So in long run, I believe their team will develop more usability for the token, run more marketing and others. Then price will grow and because they are backed by good teams, good platforms they will have sustainable growth
Meanwhile, if you can get earning by locking your token, it is good so why do you have to skip it. Actually, others should do the same as you did.