There's a fine line between doing a thorough job and going straight into overkill territory. A thorough job shows that you've watched all the details in something you're doing and prepared for the very realistic ways it could go wrong.
Overkill, however, is approaching a job with the expectation that aliens will invade soon after the job is done. Like, ensuring that none of the pipes in my bathroom will leak is appreciated, but I could do without the howitzer they installed in the window.
Of course, that's just me. As we're about to see, some people might appreciate the howitzer too.