What hinder businesses related to e-commerce to utilize the Steem blockchain for their transactions within the platform?
Probably the biggest problem for eCom coming to Steem is the lack of robust storefront dApps. There are many indie authors, artists, and merchants who would probably love to break the Amazon stranglehold on online retail, but without two things - a robust storefront dApp and a tie in to reliable global shipping for physical products, online retailers probably won't be making a major move to Steem any time soon. Right now only downloadable products would be a viable candidate for a Steem Storefront.
If a good storefront were developed, I think Steem could give Etsy a run for it's money. Add a tie in to Print on Demand outlets and you'd be giving RedBubble some serious competition. Figure out a dApp that worked with international shippers and look out Amazon here we come!