I recently had a discussion with a colleague regarding the exact meaning of the phrase "it would not be a crime to do sth." in the context of accepting a paper for publication. Specifically, a reviewer wrote
"It wouldn't be a crime to accept the paper."
The argument was whether or not this simply means it would be OK to accept the paper, or if the statement had a stronger, negative connotation. Unfortunately, a google search mostly produced results with a legal context.
Crime is used also figuratively outside legal context:
If you say that doing something is a crime, you think it is very wrong or a serious mistake.
A language is a finely tuned instrument which it is a crime to damage.
It would be a crime to travel all the way to Australia and not stop in Sydney.
(Colline Dictionary)
It probably means the reviewer does not like the paper.
This is similar to damning with faint praise, where carefully limited praise is used to deliver an oblique or unmentioned criticism. Compare:
It wasn't the worst paper I ever read.
It wouldn't be the worst thing to accept this paper.
Think about this contextually: the reviewer says that it is technically not a crime to accept this paper. The reviewer is supposed to evaluate this for publication and give an accurate recommendation. This is far weaker than saying, for example, "we should accept this paper." If I were an editor, that faint praise would give me serious reservations against accepting the paper.
There is a lot of range between "not a crime" and "we should accept this paper." The reviewer could be even more strongly opposed to the paper, but they don't think it merits their support.
You might consider "blameworthy".
"It wouldn't be considered blameworthy to accept the paper."
