The age old justification of "if I don't do it, someone else will". You can justify many things with that.

I happen to think this particular technology is cool and it's silly to be afraid of it, but no need to employ that justification.

But I think some things are justifiable by that argument. A great example of that is the public disclosure of software vulnerabilities. If you’re not malicious, and you find a bad bug, chances are a malicious actor will eventually find the bug too.

Doing X to mitigate the harm of someone else with bad intentions doing the same is not in the same category as doing X because "it's cool" or "money".

The equivalent example would be: "I might as well hack this account and take all the money because if I don't, someone else will".

I have no problem with: "I should inform the developers of the vulnerability (perhaps publicly to pressure them) so that it will be fixed because someone will hack it otherwise".

We were literally talking about building technologies that might be used in harmful ways. Discovering and developing software exploits is a direct example of this.

Further, if enough people refuse to accept that justification, you _can_ make a meaningful difference. Maybe can't stop it, but as the number of willing engineers goes down, the number of things that can be built in any given times goes down. This gives society and the law the time to take up with and process the implications of the technology.