8 years of people staring at nothing but spell timers and rotation cues, watching strategy videos, and using theorycrafted highest-dps builds and rotations seem to have made people lazy and entitled.
It's hard for a change! Enjoy it! You'll get your strategy videos soon enough. The game's been out two days! TWO DAYS! If you can't figure it out on your own, wait a month and there will be tons of resources spoon-feeding you step by step exactly how to beat the entire instance.
I think they did it right by upping the difficulty on the dungeons, they're not supposed to be your everyday zerg fest like the ones you see walking around Queensdale. You're supposed to be damn good at the game, knowing how to use your bar correctly, positioning, evasion and coordination + synergy with your team. If you've played GW1 none of this is a surprise, hell I was doing DoA with heroes only and it was only doable with top-notch play. I'm glad I see this returning to GW2, most people that didn't get that far or are just used to the holy trinity are gonna have to up their game and deal with it, becausing dumbing down the dungeons aren't the way to go. Players should improve and let go of old/bad habits.