This is actually a pretty profound insight. lol You're absolutely right! The constant grind, the need for instant gratification... Dungeons and other game content could be designed VERY CAREFULLY with things like trap mechanics, cooperative play, or varied puzzles that everyone in the group needs to work together to figure out. But no, we get a straight shot through a pretty cave with a boss fight every 3rd, and 3 or 4 mob pulls that, when overgeared enough, can all be pulled together into one AOE spackfest.
The issue here is the old Cost vs. Reward argument, right? If content is carefully tooled to fit in with the carefully designed/thoughtful model, players will complain that the dungeon takes to long to complete, isn't any fun, is too difficult, etc. If it's too straightforward (As they currently are, in my honest opinion...) other players will complain that it's too easy/treadmill/lootfest/gear grind. Finding a balance is a very difficult thing to do, and I honestly don't think ANY MMO has found it. Ultimately it comes down to the rewards for the dungeon/challenge in the first place. I rather like the primal fights. I think these one-off fights are a really good addition to an MMO like this, where you can go in, not worry about trash, fight a badass boss with cool music and unique(?) mechanics, put the puzzle together, get a team together that can handle it, and get your loot. This is a wonderful wonderful thing. Unfortunately this concept is repeated throughout the game in it's current design models. Regular instances are treated like Primal fights that are inconveniently long, when they should be treated as something else entirely. Same with Coil and Crystal Tower. I do hope that the team finds a way of making dungeons far more unique, and offering rewards that are worth the wait and the effort.
To address the OP (Wow, this is turning in to a book. ><), I personally like to have fun in dungeons. I always attempt to at least greet my fellow DFfers, and if they engage me back I will attempt to make amusing comments and keep things lively. Not everyone appreciates this and I'm often rewarded with silence (And a total lack of commendations, which is poo because I think I'm freakin' hilarious and my DPS is always top-notch...). Other times it totally pays off and we all have a grand time (And forget, just for a moment, the insufferable Tomestone/Gear/Light/RNG Drop grind) that we're engaged in (And occasionally a handful of commendations!) If I have a friend along and we're able to banter back and forth a bit, it usually gets even the more tight-lipped zombies to mumble something other than Hello (Or "Braiiins" as the case may be!)