Gee, I am not sure what your problem is. Perhaps you should take a break from the internet for awhile, I do that sometimes and find it refreshing. I don't suppose that you even know what IIS stands for so it I rather pointless to continue this part of the conversation.
To be clear, what any of us have done in the past really is not relevant to this discussion, our opinions should stand or fall on their own merits. I'm not sure why you are so opposed to the idea that software must be able to handle bad input; if we were perfect in that regard then there would be a lot fewer successful hacks. (Note that I'm not claiming that the projects that I worked on were that way, far from it if you know what IIS stands for.) It is a bit of a weak analogy to the MCAS problem but I lived through a time when we tended to ignore bad or unexpected input (I don't suppose that you know what strcmp() stands for?) and the software industry suffered greatly.