When scientists want to publish their results, the paper first goes to one or more referees (usually anonymous), who advise the editor about the quality of the paper. It is common for referees to ask why the original author(s) did not consider a particular question as part of their work. The reply in the cartoon is commonly used by the author to defuse that question, essentially saying we didn’t consider that question because it’s too much work, and just publish what I’ve done already, dammit.
And “we need to fix this” usually means “someone else needs to fix this”.