The topic of UB is continuing to create controversy as the number of non-Magic IP products explodes. The Professor put out a recent video on the topic predicting a future Universes Within product to make up for all the unique UB cards being added to the mix, but looks like MaRo has quickly shut that idea down.
What are players who don't like UB supposed to do when there are no Magic versions of those cards? This is now just reality.
If you're just playing with your friends you can just decide to not use them or make custom proxy versions for the cards you really want to play with. Or you can just play limited, either with a set that doesn't have any UB cards or with your own cube.
Otherwise I guess you can either learn to live with them or just stop playing. For me it's mostly the latter. Universes Beyond, along with absolutely insane power creep especially in Modern and an overwhelming flood of increasingly expensive products have really taken the fun out of the game for me.