No, Windows Defender is not a piece of shit. It is adequate. This said, I never would use it, because it is used by vast majority of pc users, this means that most viruses are written to try and circumvent it. There are a lot of far better antivirus programs out there, I regularly read tests and change the one I use every several years in case I am not satisfied with my current one anymore. Never had any problems with viruses or compatibility problems with any windows updates. Or false positives from here, including this update.