Sch have been unhappy from around the launch of Stormblood for various reasons. Every single update [especially from SHb on] the jobs get sch is made worse [but not necessarily weaker] I saw someone else here mention that the changes to Drk have been like watching a car crash in slow motion and I'd argue that sentiment applies to Sch as well. There might be disagreement on the granular elements people are not happy with and it will vary from person to person but it just feels like every decision the devs have made regarding sch [and healers at large] for the past 5 years has been more perplexing than the last whilst also just getting the news that it's gonna be another 2 year wait before their identity issue is addressed while in the meantime even their glams aren't safe from being meddled with.. it's like death by a thousand cuts. Finally finally Sch seem to be more united about these changes because they not only affect gameplay but now encroach on aesthetic elements which means finally it's something that confident players and casuals both care about.
