My husband and I ran dungeons as soon as they became level appropriate {and before in several cases}. Our second group {the paladins/hunters} we did instances almost exclusively because there was just too much gathering in too many places. We did quests and questlines we felt we had to do, and hid in dungeons the rest of the time.

With that in mind, what's the point of gear designed for level 74-79?
Well, I guess it depends. My hunters came up having blown through Outland, started them shortly before Wrath was released. They literally hit STV with starter greys in some spots. They hit Outland with some gear as low as 23. They hit Northrend at 68 or so still schlepping along in some low-end Outland greens. They never touched an Outland Dungeon {except at 63 to tame a wolfie in Ramps}. They took every bit of gear they came across, dungeon or quest. They would havve been nothing but a detriment to our paladins otherwise.

Our paladins, however, were geared to the teeth in epics from BC. And all the quest reward plate was nothing but DPS plate. Ardath is still wearing the Sunwell breastplate, she was wearing level 71 bracers until 2 days ago. A lot of her gear was the same stuff she'd been wearing for months, the itemization just wasn't there for plate casters and what was there was often a sidegrade at best to what she had. The pallies had pretty much no upgrades between 70 and 80 until they could use crafted gear and get drops from heroics.

Long story short, some people need it, some don't.