I recently had occasion to speak with an American academic who has written extensively on Darjeeling.
We discussed GI briefly and her findings about attitudes towards the system in the region among tea garden management. I was surprised, but, not shocked to learn that planters are not necessarily in favour of the system given that it adds expense to their production process.
This finding by the individual gave me pause for reflection on what the purpose of GI is. As a system to identify, essentially, taste with place, GI is aimed at creating a unique identity, protected at law, for a given areas' product. Colombia has coffee; Scotland has Scotch; India has Darjeeling (among other tea areas protected by GI).
That the system, in the short term, costs, and is an expense that impacts a planter's bottom line, is inevitable. The bigger question is, what impact GI has long-term for Darjeeling, given that 40x more tea is marketed as this rare and fine product, then is actually produced in the region.
If GI does have an impact on reducing the falsely labelled product - as a certification mark is integral to the system - then, I would posit it is a good system who's costs are justified. Indeed, one could argue, with much literature to back it up, that other certification systems also impose a cost on the producer. For Darjeeling, this cost is a guarantee of purity, which, long-term benefits both producer and consumer as it creates a sustainable, future market demand related to tying a unique product to a specific locale.