In think the reason some are asking for a Herbalist station in Midway is matter of convenience. I'm sure they are all aware you can take the ferry to other locations.
Not to mention not everyone has access to the ferry.
Caliban mainly. Our man crafting outlet is just the herbalism cauldron in the drain. To do metal working efficiently we'd have to go to the mountain and and mine then we have to go to dveirgheim, and hope a certain dwarf isn't there to kick you out of the place. Since you obviously can't go into Vallakai as a caliban that makes things a tad difficult, midway haven alchemist guy is rather racist so you can't perform alchemy. You can wood work at Degannwy rather nicely.
I wouldn't be entirely against a herablism cauldron at midway, i'm not sure it is entirely necessary infact I think it's more boosting for the people who can just go everywhere, you can go out farm in the wilderness and go to the station... things may very well be too easy.
On a side note though and not to hijack a thread, it may be a good idea to add more crafting stations to various places. So just something to think about...
I'm sort of game for a herbalism spot in midway I don't see the direct harm although it would make the craft amazingly convenient.