The herbs are all going to one person. It as if multiple guys are handing their product to one guy to get all the credit. As if his effort multiply by the number of chars. I see that unfair, the benefit is more than paying their salary (the subs) if he paying any or just buying tokens from farming. It is not only faster but more beneficial and could destroy the market buy flooding the AH.
And I misunderstood you for buying boosts as I though you are talking about level boosting that bought from the shop.
This is only true if nobody else manages to snatch a node before that person. I did a small tour around and didn’t find such a fierce competition though. I guess mileage varies a lot.
I can see Blizzard implementing counter-measures though if they actually notice the practice getting out of hand, but IMHO if they do anything it will be more towards farming mechanics reducing the advantage of group-looting a node than prohibiting multiboxing.
That’s also pay-to-win technically but IMHO it’s far less compromising the integrity of the game than paying PvE/PvP boosting for loot, achievements or rating.