It is not just that. Some people in this field just have questionable ethics, unfortunately.
Some are just childish and have this close minded ignorant macho attitude that though men, as they style themselves, should not care about ethics.
Then there others who just don't care either way as long as they get paid to play with their toys.
+1. I'm a foreigner from Mexico-- back there all engineering majors study ethics in school as part of the requirements. I studied abroad in the US, and was surprised at how not only there was no ethics requirement, but many engineering majors actually shunned anything having to do with the humanities in a very "us vs. them", "we do real work", "this is not important" manner.
It's hard to measure what impact a couple of classes could have and it would certainly vary from person to person, but it would at least set the stage for conversation and be an acknowledgement to the importance of ethics in engineering.
To add an anecdote to the pile, I went to school in the US and had to pass an ethics in engineering course to complete degree requirements for Computer Science in the late 90s.