I find it fascinating that the original post's "We need a jew" was unacceptable, but the modified post of "We need a Shabbos goy" is perfectly fine. Especially because in the original post the moral failing was the christians', whereas in the modified post the moral failing is the jews'.

And even more so because I too feel emotionally motivated to dislike and down-vote the first while supporting the second, specifically because the first one feels anti-semitic and the second doesn't... even though the opposite seems to be true.

Perhaps it's because the term "we need a jew" signals ownership, resulting in objectification and degradation of the subject? We need a Robin Hanson in here!