In the official survey done for MagicCon: Chicago, 87% of people who tried the bracket system said it was helpful in their games
If you don't understand that a word is being used in a way outside of its normal meaning, then you also don't know to look up the new meaning
An infamous example from Shadows Over Innistrad was for Descend Upon The Sinful, which in French was translated to "Fondre sur les pcheurs", which, thanks to the incorrect diacritic on pcheurs, means Descend Upon The Fishermen
At first, this looks like a much, much worse Ghostly Prison, in that it doesn't actually stop attackers
The biggest concern I have about keyword counters is that because of the pandemic, we never really got to see whether they achieved their goal of clarifying garbled boardstates