

Bullshit.
People act like all decisions by Blizzard are made by a singular person every time. He was Assistant Game Director in 2015, and became the actual Game Director in 2016. He had a big say in things, and actually was responsible for a lot of big changes, like Multistrike, even before he was the de-facto Game Director.
Legion was a dogshit expansion at launch, with probably the most ass-backwards design decisions, and the expansion got saved by the later patches. It was Ion that saved it, not Chilton.
The thing about Legion is that what made it great was the content, but more importantly that it was a fresh take on WoW after a disastrous one.
It did things adequate, but more importantly didn't do anything disastrous like BfA with its awful plot turns, or SL being severely hamstrung by delays.
SL should have been something similar to Legion. The lore is not great, and the plot is kinda boring, but it's not leagues worse than Legion like BfA was, and the way the expansion is set up with a more distinct line between what is and what isn't important for raids is close to what Legion did in making the overworked worth a damn.
The only thing I am able to confidently state is "better" than BfA and Legion is the nebulous concept that it was more "fun" in that it incentivized overworld content to a greater degree.
The world revamp dream will never die!

Legion was combination of fresh ideas (some good, some bad, as always), long wait after very barren expansion and culmination of story that started Warcraft for many (most?) people. And proof that Blizzard shouldn't give a shit about min-maxers (9.0 kinda proves it too, but in other way).
Despite fact that 7.0 was objectively worse design that any patch after it, hype was real. Cause it's better when hardcores complain doing Maw of Souls 24/7 or RNG legos then casuals complaining there is 200 item level ceiling and leaving game.
Legion is a good example. Imagine being stuck in Emerald Nightmare for months with its awful Legiondary drops, getting the Suramar stuff and Nighthold long after it was needed, and then being stuck in that raid with only small amounts of extra content outside before getting 7.2 as a weak ending to the whole thing.
It would have been awful, and just like in SL would have magnified every single flaw from sheer boredom as you are stuck with miniscule amounts of content.
The world revamp dream will never die!
Yes, because they are Blizzard and they have a massive team of talent readily available and covered as far as $$ goes. Focusing on some public target dummies like Ion and Danuser is just dumb. First of all they are far from prime evils you make out of them and secondly you have whole teams of designers that are pumping great stuff for many many years.
WoW's art, sound and music are still top notch. Encounter design, dungeons, questing - it's all there. The key pieces that allow them to craft great expansions and content patches are all there.
They need to wrap up SL and hopefully not end up burning shitton of time and effort on yet again trying to reinvent the bicycle like Torghast and put out a solid 10.0 with a lot of base content and meaty content patches on time. They have the talent for this.
And BTW, let me spoil it for you - Ion is on his way out and not because "Ion bad and getting fired", but because he has the creds to score better opportunities elsewhere and maybe get a vacation from being public enemy no.1 while at it.

Sure, game development is obviously a team effort, but Ion is not "a dev", he is the Game Director. He is the #1 guy of the WoW department, alongside John Hight as the Executive Producer. There are plenty of other talented people on the team like Morgan Day, Jeremy Feasel, etc who I'm sure all come up with very important ideas, systems, and content.
However, these 2 dudes have to manually greenlight every single design decision thought up by another developer. All the ideas, good and bad, go through them. More so Ion than Hight, the latter of which is primarily concerned with making sure the product development is on schedule.
That's a level of responsibility you can absolutely pin him for failing. Sorry not sorry. The CEO of a company is still canned at the end of the day regardless of whether the decisions he made lead to thousands of other employees doing the actual work (and not succeeding). Because responsibility is a thing, and it goes hand in hand with consequence.

Tbh, I'll never EVER understand why people glorify Legion that much.
Imo, it was 1 of the worst exps. It's the point where it all went EXTREMELY downhill.
borrowed power grinds
rng legendary items
COMPELTELY ruined pvp
completely ruined professions (crafting especially)
community boosting shit-fest came live in that expansion
removed pvp/pve vendors
introduced countless ilvls per patch (from 2 'tier sets' per patch, up to 4+ )
DESTROYED/homogenized classes.....
etc, etc, etc...
I don't think Legion was THAT bad, but it was shat on despite what MMO-Champion forums have you believe.
#TeamLegion #UnderEarthofAzerothexpansion plz #Arathor4Alliance #TeamNoBlueHorde
Warrior-Magi

Because Legion had SHITTON of quality content all the way from great raids and dungeons, introduction of M+, class questlines with unique weapons/halls, new class AND it had some amazing areas with Suramar.
That expansion was huge.
The stuff you mention are mostly mechanical issues, but it does not change the fact that Legion was amazing expansion overall.
One of the worst? Bruh... what are you even smoking.