It's terrible design really.
There are some bad players, but it's mostly the game's fault. The NM's aren't hard, they are just a grind. They are identical every time, so all you need to do is know the strategy, and someone just tells you... So there is no trial and error in this game, and no having to "work things out" because it's just not designed like that, guilds don't keep their leet 'strats' close to their heart, because everyone just wants everyone to know how to do it so you can blast through the NM, get your loot and go to bed.
So you are handed the strategy, and it's fairly easy to perform too. If a big white shape appears, don't stand in it. Little more than that.
What makes it hard is that you do very little damage as a dps, and healers/tanks struggle more or less the same way. And the insane thing is, your character will NEVER get any better because NM gear is the best gear... So you 'somehow' have to win, because only then will your damage rating go up from 2.8 to 2.9 or whatever. And that's if you win the roll on the loot. If you don't win the rolls, or if you fail and someone rage quits or something, you are locked out until the next day. So it's slow progress, and very grindy and quite painful for most people. You also generally just can't get in a group if your rating isn't high enough, because people only want an easy ride, so it's total catch-22 at that point of this game. Super crappy design.
It took me a lot of pain to finally get through a few NM's, finally got to about 3.0 or something, which was still far too low for anyone to want me. So I mostly only got in groups of shit people who were either idiots, or like me they were just doomed to having bad gear. But struggling through that for a week or two and I eventually got to 3.2, then I got in a group that was quite good and I got a lot of loots and ended up 3.5 or something. Then the next night I logged in at the same time and the same group was there and they invited me again. Before I knew it, a few nights of that, I was about 3.8 or so, and then I could get groups easier. But of course, at that point there isn't really any point going any higher because there isn't any content to make it worthwhile anyway.
So it gets easy eventually, but when you think about it, that makes no sense at all. It should start easy and get harder, but in TSW, it's almost impossible for people when they are starting out, and once you have done the dungeons a million times and can do them in your sleep, you can get groups instantly and you can blast every mob down in seconds.
I kind of like the technical aspect of these modern 'instances' that MMO's have. But I don't think they are good gameplay. Maybe if they advance in the future to the point where there is a lot of random things happening, it could be nice. But imo, these kinds of theme park ride games are so hugely inferior to a couple of old school games I love, before instancing existed.