Neither even acknowledge the region locking. ( to be fair, customer support doesn't know any of that )
They can easily decide that they won't carry region-locked software (they didn't). They can easily decide to fix their broken storefront to not show misleading and false data (they also didn't).
Unless you're Netflix or HBO, few business have the resources to release a video product in multiple markets. It requires translation (subtitle or audio), marketing & advertising, financing, distribution, customer service, and many other invisible functions required to run a business. When you're a ~20 person studio, that's a little out of your budget.
This often requires working with a separate distributor in each market that can provide those services, including taking on the financial risk of distribution in exchange for profit share.
In most cases Steam is just a naive distribution platform and the last step in the "supply chain". It has VERY little impact on the overall success of the project, but helps simplify "last mile" distribution by getting the final product into the hands of customers - only instead of DVDs being shipped across the country in trucks to CostCo, we have Steam.
>> They can easily decide to fix their broken storefront to not show misleading and false data (they also didn't)
The responsibility is on the business managing a Steam account to ensure this data is accurate, not Valve. Same system is at work with the Apple, Microsoft, and Google app stores.
http://i.imgur.com/N3dEPjE.jpg
The image above doesn't do justice to how bad the experience is as a customer, the tv show is already released in the US, but they make international customers wait to watch it. ( after buying it as if it was fully released ) and of course customer support tells you to post in the forums for help...