You have to that this is not a power level system, it's a play experience system. There are extremely powerful decks that don't use any of the "staples." Notice how the targeted categories are tutors, gamechangers, land denial, infinite combos etc. These are all things that warp a game and can lead to a negative play experience for people who aren't g up for that. Yes many of those cards are powerful but there are plenty of powerful cards not on the gamechanger list because they aren't as salty or game altering.

Additionally, your point that people will work around the brackets to still have powerful decks seems to presume this doesn't already happen lol. If people care that much about winning/pubstomping they've been doing it even worse up until now and won't stop. This is much better than a point system like Canadian highlander where everyone optimizes to the top of the point range.

So I say it's better than nothing and if people abuse it, they would have abused/lied in the rule 0 conversation already so I don't think it's possible for the system to "make things worse" or "backfire."