The ShiftstonedEternal Power Calculator is a deck-building tool that visualizes your odds of drawing enough Influence and Power based specifically on the cards found in your deck.
I think it's because you can get it back out with your merchants if you put it into the market (which you cannot do if you put a Seek Power into the market). Kind of a clever innovation.
That's an interesting point. Though to be honest I don't normally get a lot of swaps going between market and hand unless I have a deck with mirror image. Which you do get with Howling Peak but it seems unlikely. Still it's a good point.