At the big companies, HR doesn't handle the complete hiring process, but a good HR department can do effective pre-screening for the hiring manager. I like the fact that the OP points out that if you provide sufficient criteria to HR, they can effectively screen resumes. (The problem that I've seen - which can be avoided - is that either no criteria are given to HR or the criteria are too tight.)

Why should an engineer spend time pre-screening for typos? And, if the hiring manager is adamant that the candidates must be proficient in language/methodology X, why should an engineer waste time looking at resumes that don't even mention language/methodology X? (Maybe the hiring manager shouldn't be adamant about lanauge/methodology. Maybe judgement should be used. So that's a criterion that should not be passed on HR, in that case. If it is, that's the fault of the hiring manager, not HR.)

Also, a good HR department can keep you from getting into legal trouble with illegal questions/behavior.