I completely agree with OP. Zergfests with sometimes invisible mobs are not fun, in any way. I did them when leveling because they gave WAY too much exp for the nonexistent effort (they should tone down the exp a little and balance it out with slightly higher exp in dungeons imo), but it was very boring. Do I think they are a good thing to have in the game? Yes I do, the more options and variation people have the better, everyone likes different things and even I who don't like them even I actually liked having them as a part of the leveling process in some form since it gave you a break off from the normal monotonous quest grind (even though I enjoyed the story).

As for FATEs replacing NMs entirely I don't understand it. No it is not the same thing to have something pop that hundreds of people rush to zerg down (people in beta said "wait and see til endgame FATEs they will be much better", well I've waited and they are NOT any better), the whole experience of the fight is completely lost (It is such a freaking waste to throw away amazing mobs like Behemoth and Odin on making them FATEs). This also applies to the competition part of it, I loved the challenge of claiming a mob so me or me (loved to solo) and my friends (loved to lowman) could kill it for a possible drop even though a lot of the time you lost the claim, FATEs give neither of these really. Bots were a non-issue with regular NMs so that is just not a valid complaint. As for HNM I think there are solutions to the problems with those and we should have them too because it adds to the overall experience, but AT LEAST regular NMs should be in (Make it drop the same things you can get in instances or w/e it doesn't matter, it doesn't have to be exclusive to the NM).

Overall though I think the game needs more incentives to explore and travel the world even after you ding 50 and don't need exp anymore. Hidden areas and treasures, hidden NMs with obscure pop conditions, things like those that are in the open world. And no I don't hate the game I am having a great time, but that does not mean I don't think there are things that can be improved upon (ignoring even obvious things like login, /tell in instance etc issues).