You are arguinng a strawman. We are not discussing bugs or maintenance, we are discussing a person acting maliciously. Furthermore, you are talking about people being "stupid," which has no place in a discussion of whether a person giving away code has an obligation to not act maliciously.

Never in the history of the courts has a defendant's lawyer gotten up on his hind legs and intoned, "But your honour, the plaintiff was stupid," and had the case summarily dismissed.

Naturally, one can make arguments about what precautions the user of some software ought to reasonably be expected to perform to avoid harm.

I agree it may be prudent to assume that every maintainer is malicious and sits up all night trying to think of ways to put malware in your compiler, but I do not agree that this is going to be an effective defence in a court of law if you actually put malware in a piece of software that you give away.

Now please excuse me, I am about to audit every last line of code in Unix. I have no more time for exchanging pleasantries with you.