You're not wrong on the first statement. I am doing what's convenient. But I am also doing what I can with what's laid out in front of me. Basically every single company in my field has ties and contracts with military, so what, am I suppose to just change careers? I enjoy what I do, and I think military projects are neat in the technical sense, but that doesn't mean I want a part in it.
I'm not an idealist. The world isn't black and white.
Of course. If you like to make ice cream and the only organization employing people to make ice cream is the mafia, you stop making ice cream professionally.
You should absolutely change jobs if your current one is immoral, and careers if it comes to that. This much is obvious.
The problem is in the hurdles making that difficult or unrealistic. In America, this process could leave you and your family homeless, maybe bankrupt if anything goes wrong. This fear leaves (maybe most) people in jobs they know to be immoral, and society is that much worse off because of it.
I think you should be doing whatever you can do* to create a society in which people are not forced to act immorally, such as you have been.
I'm not an idealist. The world isn't black and white.