I think it's a mixture of them nailing the new combat style (if they did even an okay job there would still be a lot of salt) and the popularity of the Soulsbourne genre (even though I don't think it's the best comparison, it's close enough to where I can see the resemblance). I'd compare the combat style more to Sekiro than any of the original souls games tbh, they've got the same idea of strafing around your opponent instead of rollspam and a "meter" where once you've done enough damage the enemy staggers and you can go in for the kill.
You do get some combo strings through the skill tree, but yeah they're not nearly as long as the ones you'd find in the OG trilogy. There are certain moves you can link together into those combo strings though, so at least there's that. I honestly think having longer combo chains isn't something impossible for the next game, they won't have the work of completely changing the combat and so they can put that effort into improving what's already there. Having DMC style combos in this new system sounds amazing.
Like
Wunderwaft
said, hack and slash will be fine. Platinum pumps out incredibly sound ones like it's nothing (Nier, Astral Chain, Bayonetta, Metal Gear Rising) and DMC V did amazingly like you mentioned.
Your disappointment is completely understandable though, I'd feel the same way if one of my favorite series' changed so drastically into something I didn't enjoy.