I have to reiterate what Danramos is stating... Flash is not a standard. It is only one of the better methods for streaming video that came out on top of Real Video and even Quicktime in terms of flexibility and whatnot.

But Flash is much more than video. To concentrate on just that one aspect is cheapening what a tool Flash can be.

And people who don't include it, have their reasons. I might not agree with those reasons, but it makes sense to them.