In my opinion it's better to make a separate wof for non-premium users with different rewards or the same rewards with lower chance of winning big prizes.
Premium users with thousands of Funtoken in hand(bought at higher price) deserve to have better chance in wof. Multi accounters are milking wof and you lower the chances for all accounts, this isn't fair.
Yes, I agree with you, otherwise it doesn't make sense to invest in FUN tokens anymore, unless you are a big bitcoin investor who will benefit from the extra daily interest feature over your bitcoin balance, because it's no longer possible to rely your investment on the wheel's returns.
Now besides FUN price going down you can't recover your investment decently through the wheel too. I know the site can't give more money than they earn and that it's their right to change rewards' rates anything they want, but it's an undeniable fact it's a quite frustrating situation for investors.

Nobody buys FUN expecting the rewards will be drastically reduced overnight.
Well apart from the extra daily interest feature, don't forget you can also earn some cryptos from your FUN token investment through the premium member cashback feature and the FUN saving one. And even if the WOF spin ROI is reduced, it's still a free game where you are earning some free satoshis each time you play. So if the FUN token price stops to go down, it still could be a very interesting investment for newcomers. I just hope older investors will refrain from dumping their FUN token bags.