This has been my experience as well. When I've been able to identify and directly contact the actual hiring manager, they seem delighted to talk to me and always lament the complete lack of qualified applicants (none of them ever got my resume passed to them from HR). So far I've ended up turning down most of these offers, but you have to wonder how many other qualified resumes the hiring manager never even sees.
Any communications with HR, even if addressed to a specific person, are just blackholed. I have no idea why companies even have these useless departments or if there are actually any real people in them at all.