Part of the point is to keep users here and participating and not send them to CNN, Fox, or any other site. That doesn't add value to Steemit or its users. The exception of course is those crossposting to both Steemit and to an external site with their content. Reddit and twitter can't make money on the concept with advertising revenue. Neither company has made a profit.
There is also the problem of digging through a site filled with links and copy/paste to find actual original content. Those that do post original content will not be seen and leave.
Posting links isn't discouraged here. It's just encouraged to add your own thoughts and comments on what you find. This prevents someone from posting thousands of links a day with a bot and it adds original content to the site.
Sorry, you pricked a nerve, I've spend the day chasing down steemit-abuse. There is a lot of people with time and money invested in Steemit that don't want to see it become another site like Reddit. After all there is Reddit for exactly this purpose and pretty soon there will be "Screem". A twitter style site that runs off the same blockchain Steemit. There will also be a Craigslist style site run on the same blockchain.
Since Steemit/Steem is open source, someone can create a Reddit style site as well.
I appreciate your thoughts. I do think making URLs explicit might even reduce copy pasting though. The same goes for finding original content; I think it would reduce copy pasting and make people able to for example filter for original content. But I can see how it might not fit the platform.