It's kind of the basis of the article. The European Commission is focusing on shopping as the core of the case right now, so that's what the article is about.
It's arguing that if you want to improve competitiveness of European shopping sites, there's much that could be done to make sure they aren't hobbled in the first place.
Indeed; but that's because the premise of the article seems to be that the EU is doing this out of jealousy and spite. As much as US companies may despise it but outside of their own borders they simply need to adhere to different rules though.
In the US a belligerent defiance coupled with some strong lobbying goes a long way but, like you're seeing with Uber now, that approach doesn't work as well across the pond. Likewise in this case is just about challenging Google's use of its dominance to compete unfairly in other markets (which is illegal.)
That it happens to be about pushing domestic shopping sites down the rankings to favor their own results is rather incidental; at it's core this is just a shot across the bow to make it clear that if Google wants ad-money from Europe they must play by Europe's rules.
I hope Google gets that because these are not relationships you want to become adversarial or else someone might just decide to close the little tax loophole that lets Google escape taxation of its EU revenue.
It's arguing that if you want to improve competitiveness of European shopping sites, there's much that could be done to make sure they aren't hobbled in the first place.