The problem is multi-club ownership. It should never have been allowed and is, basically, ungovernable once they start making exceptions or coming up with nonsenses like blind trusts. Of course, if UEFA disallowed multi-club ownership it's likely they would lose control of European football's governance. So, they're compromised straight off the bat and these rules are there to add a sticking plaster over everything.
Nobody sane would trust John Textor. I can understand UEFA, now that they have bent over backwards to turn a blind eye to multi-club ownership for their own ends, taking umbrage at his involvement at more than one club in the same competition. The failure by Palace to play by UEFA's self-serving bureaucratic rules gave the governing body the in they needed to make an easy example of them. I just find it a dereliction of duty by the Palace authorities not to have played along with the paperwork. We know the rules are self-serving, but they are there to protect UEFA's interests above all others. Parish and co were asleep at the wheel in failing to adhere to those. It's so very Everton under Moshiri.
The Palace fans are being denied something won on the pitch. But the board has questions to answer. As Everton learned bitterly, when you lie down with dogs you get fleas.