I agree with your criticism that the browser ecosystem has improved from a past of idiosyncrasy and special plugins, but I wanted to mildly disagree with your strong prediction that if the browser became technically hostile to DRM, then content providers would refuse HTTP distribution and that the market would gladly go with custom streaming boxes.

Just because a DRM standard doesn't go through doesn't mean that it's any easier or harder for the majority of customers to illegitimately acquire content, and nor is it any easier or harder for a company to provide illegitimate content, especially in the centrally-hosted streaming form.

If you're saying that there's always a way to acquire content, since content must ultimately be decrypted on some legitimate system, then companies will continue to have the technical reach to efficiently acquire content. What stops them is legal censure and international trade deals, not a DRM standard.

What a DRM standard does do is make legitimate content experience more enjoyable for customers because now there are fewer plugins, which could also translate to security benefits.

At worse, we end up with a world like we have now, where content providers still do business with Netflix and Hulu, and companies use flash or some other plugin to secure their content, and people still have the same ease / difficulty of acquiring illegitimate content.