If you remove channels, the margins fall back to the content producers, independents, Warner Brothers, Paramount, Touchstone, etc. And it's much more riskier for these companies to fund shows when they can't recoup their costs if the content doesn't sell advertisements or is purchased by a subscription service. If Scandal starts making less money for ABC, they still have Grey's Anatomy and Dancing With The Stars revenue to fall back on. Then they assess and either reduce the order from the production company or cancel. It's easy to produce content when you're talking about a low budget show with no name actors. But shows like House of Cards, with big names, huge set pieces, etc, cost millions per episode. Something your average indie company releasing content online can't afford. It's all about money.