There's no faster way to totally sink my credibility, as a new team member, by making a huge fuss over something that's not a problem, or that the team doesn't see as a problem, or that there's already an effort to fix, or that there's a really simple way to fix that I just didn't see at first. There are always so many problems on a team, so many things that could be better, that I'm only ever going to solve a handful of them. Working on problems in the order I noticed them is rarely the most effective order. So the WTF Notebook gives me a place to park the impulse to fix it now, damn it! until I have more context for deciding what to work on first.
And the more egregious something arbitrary is, the more likely that there are other even more egregious things out there – so it's no sign that that's the one thing that should be top priority!