It seems that you confuse the terms "good user experience", "best solution" and "efficient to use". A good user experience is if the user likes what happens, which isn't the case if he launched the nukes accidentally. The "best solution" depends on the situation, e.g. in something like facebook, the user experience isn't a direct goal, since the "best solution" for the "delete account" function is to hide it deep down somewhere unexpected. "Efficient" seems to be what you like and what your colleague objected to in case of the "launch nukes" button that you can trigger via eye tracking by looking at it (insanely efficient!).
The question is way too vague to get a single answer. Here are some:
- Yes, doing something that is usually bad thus isn't something you want to do most of the time should not be so simple that you can trigger it accidentally or faster than you can anticipate the consequences (no simple "launch nukes" button, put a lid on it)
- No, if it's for qualified users who got some mandatory training the app should be as efficient as typing sudo rm -rf /
- Depends, if you have a broader userbase hide the dangerous stuff but add an option to enable it so after it's enabled advanced users will have an efficient way to use it.