Even popular content has been neglected/abandoned over time though. I loathe Hildibrand, though I'll acknowledge that he's popular - yet ShB went without a quest for him. We didn't get an Allied Beast Tribe quest this time around, either - despite being an established tradition for each expansion.

I'd rather not see old content removed. That's exactly why I left World of Warcraft. Well, one of the major reasons at least. Guildhests are great - quite often my Mentor roulette is a guildhest, so there's definitely players still queuing up for them.