I think part of what people are pointing out is, if you went and asked the Roku devs why they don't support arbitrary URLs, I'm sure they would be able to give

I think part of what people are pointing out is, if you went and asked the Roku devs why they don't support arbitrary URLs, I'm sure they would be able to give you a list of reasons as long as this if not longer. They'd probably make the point that most user-video content is on Youtube or Vimeo, and that for most users there really isn't much need for a non-app solution. They'd probably make the point that Roku is designed to fit a particular user, not to stream arbitrary content, that it's not trying to be a be-all-end-all streaming solution for everyone. They'd probably make the point that a URL system wouldn't allow them to support cool app-streaming-specific features like resuming play between devices, or social features like comments, or suggested content. And they'd probably tell you that of course they considered supporting URLs, and of course they considered the tradeoffs, and ultimately it just wasn't worth it. I have no doubt that the number of people who want to use URLs with their TV are a minority of the market. Almost certainly not as much of a minority as people who disable JS (that's a tiny sliver of traffic that mostly just hangs out on tech forums like HN). But probably not a high enough market segment that it makes financial sense for a Roku or Chromecast to expend a lot of time adding support.