Why do you think this is an attempt at a persuasion tactic? Taint flags in this context just means something that might be relevant to debugging. Which this condition might be, if people in the future are unfamiliar with a potentially anachronistic split between /usr/bin and /usr/sbin. The debug message isn't there to judge the morality of your configuration. It's actively improving your ability to continue to support both ways, by properly indicating what style of system it is for troubleshooting purposes.
How and why is this relevant to debugging?
Also, like it or not, the word "tainted" bears a negative connotation. It's hard to imagine that it was chosen arbitrarily.
> Why do you think this is an attempt at a persuasion tactic
Because they said so:
> As part of that we sometimes adopt schemes that were previously used by only one of the distributions and push it to a level where it's the default of systemd, trying to gently push everybody towards the same set of basic configuration [1]
1. https://0pointer.de/blog/projects/the-biggest-myths.html