I wouldn't call it a defect or a bug. It's simply people being ignorant and don't care about security. Surely you can call someone writing code as programmer or developer. But still, I highly suggest every developer extend their skill.

Maybe it's because I like computer stuff and I like knowing random stuff. I have a wide range of shallow knowledge about a lot of things. It might take time to build up. But from my personal experience, they are super useful when I need to go deep in a certain route.

I mean, it's not illegal if you just write whatever code is specified by your boss and call it a day. But still, I think one should hold enough responsibility for their work. If you can't do it perfectly, at least give a warning or declaimer to point out the defects.