I think people like to be optimistic about Chemist's design. Even within the restrictions of an mmo trinity system it could certainly be creative and engaging. The reality however is that they did the exact opposite with SCH and AST, turning their unique and interesting playstyles into mostly doing the exact same thing across all 3 healers.
So it depends entirely on whether you're an optimist or not and believe that with 6.0 SE will diversify healers again and make them all engaging and unique.
The people who have become jaded by Shadowbringers however look at the way healers have been going, combined with SE's refusal to talk about the complaints, and came to the conclusion that you seem to have come to.
The biggest problem is that SE is very tight-lipped about their design. If all previous expansions are anything to go by they won't change the current healer design until the next expansion. This means we'll have to wait until the job previews or even the launch of 6.0 to see whether or not the healer design will be any better. So if Chemist were to be the new healer it could be great, or it could be the same thing as the 3 healers we already have, by the time we know it's basically already too late.
