How to give advice

[Sigma-Astra]

Excluding jobs based on what they can contribute to your group with respect to other choices is not and never will be toxic it's done for even reasonably competitive or serious content. If you have an issue with it, take it up with whoever is in charge of balancing classes, not other players.

Why on earth would I blame the devs for other people excluding certain jobs because they decided that catering towards themselves and the meta compositions is more important than being a decent human being online and offline?

No, I blame the human being behind the damn screen, not because the developers can sometimes be incompetent. The developers being incompetent is not an excuse to act like a bully towards other who favor certain classes and then ostracize them from said content. They deserve, so long as they bring the skills to back it up, to enjoy any piece of content as any job with the same amount of importance as you do. Any job can do casual and Savage content, I call bs on that. It's the person playing that job that determines that, not the job itself.

If you're ostracizing someone else from your static simply because of the job they play instead of their own skills and effort at playing said job, then yes, you're being rather toxic.