I feel like the solution that's most likely to get them to budge would just be to print an artifact or colorless spell that can destroy an enchantment.
Hex Dispeller - 3
Artifact
Tap, Sacrifice Hex Dispeller: Destroy target enchantment.
I know Maro has said they cost colorless answers higher so as to not break the pie by making answers too easily available to colors that shouldn't have them.
Edit: Here's an example
mrpopogod asked: So something that doesn't make sense to me is your statement that it's ok for colorless to do things at a high cost that a color can't do. So Scour From Existence is ok but Desert Twister (or let's say a theoretical 7 CC Twister) is not ok. But mechanically I can slot Scour into a mono green deck. I thought that "not undermining a color's weaknesses" was a mechanical thing, and colorless does just that.
Maro answers: Making a Green card at any cost says “Green does that” where making a colorless card does not. Yes, you can put colorless cards in your monoGreen deck but it is not conveying anything about what Green does. Green having to go outside of Green, even to colorless, stresses strongly that the thing is out of color pie.
Or maybe this is better
roborosewater asked: Will we ever see any colorless permanent destruction that can be used before turn 7? What about colorless card advantage that can be used before turn 5?
Maro answeres: One of the goals of colorless cards is to not undercut the color wheel.