The high-profile incidents are just the tip of the iceberg. Below the surface, a constant flow of less-severe, yet still impactful, issues are a normal part of the software update cycle for any large-scale product, especially those that interact so intimately with a user's system like antivirus software.
False positives are a frequent source of user frustration and are well-documented in tech forums and reviews. False positives are a constant issue with antivirus software, and while independent tests may show relatively low numbers, the impact of even a few can be significant. It's a trade-off between aggressive detection (which can lead to FPs) and missing real threats. Both Norton and McAfee have a history of erring on the side of caution, which has led to numerous complaints about false positives.
Microsoft as the "king of problematic updates" is a common sentiment within the tech community. Microsoft has a long history of pushing out updates, especially for Windows, that cause various issues, from breaking specific software to causing performance problems and, in some cases, rendering systems unbootable. These incidents, while frequent, are often more about compatibility issues with the vast array of hardware and software configurations than a single, critical error. This is in contrast to the specific, targeted, and sometimes catastrophic errors seen in some of Norton and McAfee's updates, which have often been traced to a single faulty file or definition.