[mtlmtlmtlmtl]

The question was how GP felt about their particular unethical act, and it's consequences which likely includes multiple deaths. Since you are not GP, it seems unlikely that you can answer this question.

I fail to see the relevance of bringing up a different, and also unethical example, but I'll answer anyway. If GP said that they used to spend their time optimising software to be as addictive as possible in order to drive people into gambling addiction, destroying their lives and taking all their money while doing it, I would ask the same question.