I doubt anyone would defend that other than actual trolls. The Discovery Klingon change was nowhere as egregious as your example. It was no different than the change between TOS and TMP+
This is also a poor argument that comes up alot though.
Yes, there was a change between TOS and TMP. TOS takes place before TMP, therefore... something happened in-between TOS and TMP to cause a difference in appearance. I can accept that. No explanation needed. "something happened".
DSC takes place in between ENT and TOS.
We know what Klingons looked like during ENT.
We know what Klingons looked like during TOS.
ENT even provided an explanation as to why there was a difference between those two. It wasn't actually necessary, but whatever.
DSC... does not look like either of them, despite being set in a time period where the works have established what the Klingons look like.
It's not an apples to apples comparison. Sure, we can do all sorts of mental gymnastics to make sense of it, or just throw our hands up use the studio's explanation "that's just how they look now", but it's stupid and even THEY know it, given how they immediately back tracked on it and by S2 there was a shift back.
I'm less annoyed that they look different, i'm more annoyed that they look different and they didn't utilize such a stark difference to tell some sort of story with it. I remember the lead up to DSC, thinking... hey, maybe these "Klingons" are some kind of ancient Klingon people who have come back to retake the Empire, or they are some like, client race of the Klingon Empire trying to usurp power from the Klingons, or some other kind of cool story... but... no. They just look like that now.
It bugs me as well when you take Ash into account. Once we know he's Klingon, it was like "Oh, cool, they're going to acknowledge the augment virus and smooth head Klingons!"... nope, brutal one of a kind surgery. Damn it, Discovery. You created a great idea that had an in-built connection to established lore. Ash shouldn't be a one off, have the Klingons harness the affliction and use it to infiltrate the Federation. There's a whole damn army of Ash's out there, who eventually either get exposed or never quite make it into the Federation who end up being most commonly stationed near the border, because not only do they look like humans... they think like humans, giving the Klingons an edge when dealing with them.
I have no issue with the less egregious "visual updates", like the Andorians. That was also an unnecessary update, but it's totally fine. I can buy DSC Andorians along with the rest of the Andorians we have seen. I'm in a weird place with the Tellarites... i'm ok with them too, even though look nothing like ENT Tellarites, but they look
good. I'm more willing to be an apologist about stuff if it's good.