Most of the Internet companies survive on Advertisements. Its not an exaggeration if we say for lots of Web2.0 startups, there is no other revenue stream. And these Ads need millions of page impressions, if there has to be any considerable income. So, it will not come as a surprise if content networks and internet companies shy away from RSS.
Its in direct conflict of interest between user experience and revenue streams. RSS provides a much better content distribution channel. But that means, fewer people visiting the web page directly, and that is hurting the number of page impressions and the revenue.
"In the past few weeks Yahoo has rolled out three major new web sites - Yahoo! Food, Yahoo! Advertising and Yahoo! TV. They're great sites, but none of them has feeds. There's a reason why - eyeballs."
Of course, those three sites that Steve mentions are all very mainstream - and RSS is still not anywhere near mass uptake. But Steve is right that Yahoo has been a leader over the past couple of years in efforts to mainstream RSS, so it is a little disappointing they aren't continuing to push it in the likes of Y! TV.
The Internet stalwart, Amazon does not provide RSS feeds as well. It should have provided RSS feeds to some of its contents if not all of them. But it doesn't. Thought Amazon does not derivce any income from Ads, it needs eye balls to cash on 'impulse' purchases users make when they see products all around the page. Market Research suggests that nobody just buy one thing that they wanted to buy when they go to a store (online or offline), but atleast another item displayed prominently around the product that user originally wanted to buy. Many times, user buys some thing else than what he originally intend to. So Amazon needs more eye-balls than any other website. The same reason, why major retailers does not allow you to order what you want on phone.
Some content sites like NYT provides a teaser in RSS and force users to go the website to read the full article. But as web analytics suggest that only a few users are really interested in the full articles after reading the teaser.