I care about inclusivity, but I think you're making too much of some benign humor. Perhaps it is humor not to your tastes, but it's such a minor aberration (a couple words in a README) that I think it's unfair to judge the project based off of it. If, for example, the code outputted similarly unprofessional language into the console or something to that effect, I'd agree, but I think in this case it's really no big deal.