The App Store or Steam Sales are able to do those prices due to the volume of purchases, they've reached an audience and a pricing sweet spot that their respective clientbase expects and will buy, so you adapt your software releases around that.
On consoles prices are similar to Steam's pre-sale value, they all have sales to entice people's purchases but I think the main difference here is the volume actually obtained in each electronic shop, it's still not big enough. Until the titles sold at a lower level obtain the same benefits as selling hundreds on the higher one, they will not equal those shops prices.
That's why there is a price difference. It's decided by the market, price and demand.
Although I agree with you that this is something they should pursue.
