Not only does this create a lack of openness and transparency in the core of the web, but "big content" creators get to pass on the costs of DRM that nobody else benefits from, including to people who are not consuming their content.
Meanwhile, browser vendors will become uncompetitive - since nobody else can compete against a closed standard - and they become even more motivated to work against openness to maintain their existing oligarchy.
Could not be worse for the web.