Here's two cents on the other side - as a reader, I use the author tag every bit as much, maybe even more so. There are certain writers whose stuff I'll read regardless of fandom, just because they're great writers. I often refer people to this comm based on author, so that's how they find the work.

Also, for people just discovering the comm, and they read a new piece and really like it, odds are they are going to click on the author's tag to see if they've submitted anything else.

I'd really hate to see the author tags go. The date tags? Never once used them, but that's just my own experience.