Yep, I'm probably one of those fans. Though I also very much like the team-play aspect that usually comes with (instanced) group content. What I would like are random encounters you'd find in open world (possibly instanced) which would ~~require~~ encourage people to spontaneously group up as a team of max. 5 to beat it.
Similar to Dungeoneering in RuneScape, but with occurances/entrances randomly spread out over the open world, using your current gear scaled to the level of the encounter, difficulty/rewards scaled to the number of people in the group and the overall theme based on the current zone.
With the worst being task collections which have to be completed in order, e. g. Frode's Journal which even forces you to do/repeat the 3 SotO metas in a specific order or it doesn't count,
W T F !