Fair point. Although, I'd wonder if it's right that video is inherently a stream, and not that that's a limitation imposed by storage speeds. I might only want to watch video front-to-back, but (without knowing much about encoding) I could easily imagine that my experience might be improved by my computer having random access.
Modern video encoding is based on interpolating from the last frame, that is, only storing a real frame occasionally, and most of the time just having diffs from the last frame. ^+ This means that the data is inherently a stream -- a decoder needs to have completed decoding the previous frame before it can start on the next.
(^+ and B-frames, but let's not overcomplicate things)
It's still effectively a stream even if you skip around in time. Each frame is so large that it is a stream itself. So even if you watch a few seconds here and a few there, your use case is still pretty much optimized for streaming data.
