From what I saw the negative reviews were split between complaints about difficulty, and performance complaints. On the performance front it looked to me to mostly be shader compilation studders, which is relatively common with most new games.
Difficulty wise, yeah, it’s hard. That’s a big part of the appeal of Fromsoft games. They have made some adjustments since launch to bring the difficulty down a bit, but it’s probably better that they launched a game that is “too hard” and patching the difficulty down, than releasing something that everyone can steamroll through in a day and getting complaints that it was too easy. The game also rewards exploration, and if you just try to rush the bosses without exploring you’ll make things much harder on yourself.