I’m not one those jerks that’ll upbraid someone for top-posting on a mailing list [well, not anymore, anyway; I’m sure you could spend some time with Google, ‘email@example.com’, and ‘firstname.lastname@example.org’ and prove me wrong!], though. If someone is continuously top-posting and is using pronouns and vague allusions to the topic at hand like they’re going out of style, I might ask them, kindly and off-list, to re-consider.
The worst top-posters don’t give you any of the text they’re replying to in their email.
It’s all about context, and I think context is best given in a chronological order. That’s why I bottom-post.
… except at work, where I’d probably confuse people by not top-posting. I almost exclusively top-post at work, but my private emails are almost exclusively bottom-posted. I’m very much okay with the dichotomy, too.