For me it would depend. I did a project back in the early 2000’s for a company making military grade eye protection, goggles, and RX eyewear. I was comfortable with that and the extreme use cases made for a challenging project. A more difficult decision was when I was working for a firm and Smith & Wesson approached us. We ended up taking the project as it was for a weapon with an integrated biometric lock so only the owner or police officer it was issued to could unlock it. The fact that it was an innovation project around gun safety appealed to us.
I think that these are pretty personal decisions. It was interesting to get to know the people on the client side in those relationships as well. It was different than I expected.