The Professions menu hint says to Left-Click for Herbalism (right-click is for my other primary professions, Enchanting, which works fine) but it doesn't open anything. Should it open the Herbalism Journal so we can manage the Herbalism Specialization?

There is a few that doesn't work even using /run.
Blacksmithing and Engineering for me even before I cleaned up the code.

Herbalism is fixed now. I wonder if it is related to translations because Engineering works fine for me.

Maybe. I'm on English locale. My hunter is a goblin engineer.

That is indeed what it should do. I do not have herbalism, so I can't test it offhand. I will see if I can figure out the issue.

Herbalism works great now, thank you for that fix. I just started working on my first alt with mining, and it has the same issue that herbalism did, it does not open the journal.

The behaviour for me is:

Left-click: herbalism
Shift+left-click: herbalism [fixed this one, see below]
Right-click: nothing happens
Shift+right-click: cooking

What the tooltip says should happen:

Left-click: herbalism
Shift+left-click: archaeology
Right-click: mining
Shift+right-click: cooking

I have the Khaz Algar version of everything except for Archaeology.

(Training in Archaeologt fixed that one).