The people complaining weren't the ways actually clearing Coil but rather non-raiders with the perception a tier dying in only a few days meant it must be super easy. That mentality was derived entirely from WoW, which was at the height of its popularity back then with their Savage equivalent taking several weeks.
Furthermore, it's straight up disingenuous to say anyone asked for Gordias. The dev team has openly acknowledged they didn't test it properly; going through each mechanic individually but never actually clearing the fight from start to finish, which caused it to be widely overtuned. We saw this carry over into Midas where A6S bad to be nerfed during the tier itself because of how much harder it was than A7S. Another major factor in both Gordias and Midas' poor success rate is the lack of cross world party finder, cooldown resets, raid gear being the job specific artifact gear making in impossible to switch to another job even within the same subrole for Gordias and woefully poor balancing. Astro wasn't just bad, it was downright worthless in Gordias.
There were many, many throughout early Heavensward and the disaster that was Gordias. Difficulty played a large factor, there is no denying that. But it was neither the only one nor was it the raid community demanding it.
Much as Raven and I have disagreed in the past, he's correct in his assessment. Endwalker was mostly finalized long before the exodus of WoW happened. At best, the only bits of content not near completion would be the latter Criterion Dungeons or Raid Tiers we'll soon be seeing but the foundation was likely well underway. They couldn't, for example, decide to scrap Island Sanctuary to begin work on Bozja v2. I mean, they theoretically could but you'd get a near literal copy/paste of what already existed because they simply wouldn't have the time to develop new assets, animations and etc.
Once an expansion is near its intended release date, everything is done and dusted. Any criticisms, complaints and dissatisfaction can only be incorporated for the next expansion. Now what Square could have done to keep potential interest is be less secretive with what's coming in 7.0, what improvements and new additions they hope to achieve and what can be improved upon with the current content. We'll see in the forthcoming Live Letter and Fanfests if that happens.