the fact that the issues were missed by so many people besides the author

I suppose it is conceivable that so many people simply did not think of the impact of the story. I don't want to sound like a beta reader has some greater chance of Doing It Right than the author, but... as someone else pointed out, the beta's name usually goes on the story as well.

So I agree with you, but the betas and sounding-boards writers work with have to be looking out for more than spelling and grammar mistakes, and that's not always the case either.

Exactly. Thanks for your comment!