While Google goes straight from application to a telephone interview, a lot of companies ask for a work sample test first - either by e-mailing them a problem and asking them to reply with a solution, or through automated systems like Codility.

If you're spending a lot of employee hours filtering candidates who could have been filtered more easily through other means, I can understand feeling a bit indifferent about it.

True, but based on her little "where are they now" aside, she could have just randomly selected 98%* of the candidates she interviewed for rejection and achieved nearly the same end result.

(or whatever the actual percentage was, I don't know the total)

Exactly, and maybe the good ones did get hired and really knocked it out.

That said it sounds like the quality of candidates sent to her were really low and the upstream recruiters should have been working to improver that.

Note, however, that this may not be what the good engineer wanted to be doing. (Also, just not putting bad candidates on the good engineer's plate would be more efficient.)