Tavis' work isn't enough to significantly improve the quality of any of these "security" products -- that would take a big investment that isn't really feasible

Tavis' work isn't enough to significantly improve the quality of any of these "security" products -- that would take a big investment that isn't really feasible for a third-party. Honestly, he's just demonstrating that these products are all littered with trivially found and exploited vulnerabilities, and that they generally make their users less safe. Microsoft Defender is the only product that Tavis didn't repeatedly knock over in a matter of days. If I were to venture a guess as to why, I'd say that Microsoft's incentives are more in line with their users here. They understand secure development process and aren't selling Defender. So, they're starting from a better security baseline and have no reason to add tons of attack surface in the name of market differentiators.