It's a relic ban from the time this format was Type 1.5 instead of Legacy, basically. There's no way to abuse Mind Twist in any serious capacity, since you'll almost always be better running Hymn to Tourach (along with Snapcaster if you're so inclined) if you want multiple random discards. Or even Rise // Fall though that one's a lot harder to make the mana for now that DRS is gone. If you want to run yourself out of gas to strip your opponent's hand, then cool, but it'd be fiendishly inconsistent at the best of times, since only one Ritual means you're casting for X=2 and thus you're down an extra card basically to Hymn your opponent a turn early.
Even if the game goes long, you're more likely just going to catch a bunch of sandbagged lands or something than anything of value.