A job needs to not just satisfy those who already play it, but have broad appeal. A job that makes 12 players over the moon happy, but most players who try it with a desire to enjoy it but don't, is a failure. It doesn't need to make EVERYONE who 'wants to be a monk/blackbelt' happy, but it needs to make most people happy that this is the game's representation of that trope.
This is out of line with how most people engage with MMOs. Thematic identity is a HUGE selling point of games which offer it in general and why class/faction systems exist that merge mechanical and thematic identity in the first place. Abstract games exist, but MMOs are about as poorly suited to being an abstract game as you can get because the entire point is that it is an attempt to create an immersive experience where you inhabit a fantasy idealized identity. Saying that the thematics are 'just there to be there' counters basically everything we know about Ludology. If this didn't matter, people wouldn't be buying job crystals or commissioning art of their character doing job stuff, or making memes about jobs or gushing over DRK's story.
Job satisfaction polls for SAM and BLM are both extremely high, and the devs themselves have said they think Black Mage is pretty much 'perfect.'
There is a reason everyone loves BLM memes, but Monk memes don't exist. Memes might not be the first thing you think of when you think of a success metric for a job design, but it means people CARE about and LIKE Black Mage's identity even if they AREN'T playing it. This is going to be the primary success metric of a class in most games.
---------------------------------
You seem to be imagining I am saying 'Dumb Monk Down.' But I am not. I am saying Monk lacks any broad appeal (or, lets face it, much niche appeal).
So, to bring it back to the context of "Jobs need to be appealing even to people not yet playing them": You don't need to understand Monk to understand it is has very serious problems and is a failed job design, because jobs aren't just for the people playing them, they are (expensive) advertisements for the game getting people excited to live out a fantasy of some sort, and usually if a lot of people go 'eww stinky' to a job it means there is a real issue: Outsiders are bad at pointing to solutions problems (ex: Positionals on monks, Egi's preformance on SMN) but they are really good at noticing the problems (Monk feels empty and actively player hostile, Summoners don't feel like Final Fantasy summoners). Getting upset that an outsider explains why the job feels wrong to them is actively self destructive and petty.
You saw what they did to Machinist. Being in denial about the importance of mass appeal and community perception of a job won't change the reality of the job as it stands. They will absolutely nuke Monk as a job entirely if people broadly think it is trash and complain about it because the mass perception of the job is more important than how a very tiny group of players (who clearly don't like the job as is anyway!) feel about it.