IAmSinistar: How refreshing it would be if they could just admit "Numbers make stupid users angry! Stupid users SMASH!"
I don't think it is about angry users perception directly. It's what 'retail partners' perceive, or what publishers believe retail partners will perceive and how they will react, and the threat to the price fixing status quo.
If some of the major retailers, say equivalents of Walmart, bricks & mortar games store chains, or big supermarkets that sell a lot of games, if they play hardball with publishers and say "we will not sell any of your titles if customers can get the game cheaper online or if the customer can import" then the publisher will give into the demand.
The publisher then negotiates with Steam and other online retailers to keep the price high so it won't antagonize the old school retailers and distributors. It's easy for the publisher - lose a major source of sales or fix the price and take a bigger cut on all sales. It's easy for the online retailers like Steam, they get a nice fat mark up and don't have to compete. Then they put in place all the regional blocks and controls so that the free market is unable to find a way past the fixed prices.
Now if a business like GOG and a few 'renegade' publishers look like upsetting the apple cart and challenging the market with a more ethical approach the major players are going to start using whatever methods they can to avoid having to compete.
I can't say what motivated Nordic and Frictional, fear of losing business elsewhere, contractual agreements with distributors or only the desire to protect their margins. I'm not really convinced by the VAT argument, it's not the reason for regional pricing (we always look at pre tax prices anyway for comparisons) and I think there is more to this than is being said in the PR.