The grey market sellers have "fixed" costs to the commodities they are re-selling. They have a minimum bottom line to sell at or they lose money.
Publishers directly on Steam have no such "fixed" overhead per sale. They could heavily discount in the sales beating the grey market sellers and STILL be in profit.
That is why it is embarrassing.
I would like to see the sales trends of this versus past sales.
Personally, I miss the daily flash sales. That enabled bigger discounting as they knew it would not be long term and many purchasing are doing so on a whim so any money is good money.
The crux of the matter is, they don't want to sell on Steam UK/US cheaper than Russia/India/China/Brazil.
It's not embarrassing, it's just life. If grey market sellers are buying their games in those area - and taking advantage of "sales" like we do - they will be buying games for pennies.
You can't expect Steam UK/US to hit those rock-bottom prices. Will never happen.