Amazes me how much weighting people sometimes put in these type of tools, and start panicking because they enter a website they work on and it comes back with some red text.
Have had jobs where random marketing colleagues email the developers along the lines of "Why do we only score 7/10 in this test, 45.5% in this test, and 2 critical issues were found in this test?"
Don't get me wrong, they are useful, but people act the same way they would if their virus scanner found their computer was completely comprised. Unless the tools have a major tangible impact in something that affects the business, ie. SEO, I tend to ignore them unless they are a simple fix.