Globally, video traffic was 70% of the internet's traffic in 2015, and predicted to be 82% by 2020. 
The world is increasingly consuming video, not just for entertainment, but also for learning and gaining knowledge. Video is also a format that can be created neutral of language, with subtitles overlaid in any language later. There are a lot of reasons to make video content more useful and usable.
It's very difficult to upload video to Commons because you must use a free format for uploading and saving. We should allow contributors to upload videos in non-free formats and then convert them to webm and/or ogg as we prefer. Because this import is difficult, it's likely that video creators are going to other non-free sites to publish their videos. If it was easier to upload and then have the videos in free formats, this wouldn't be an issue and we would have more content and more contributors to the project and in the world, free and open.
I imagine the Internet Archive's conversion tool (as mentioned on Commons' help page) is open-source and could be used as a starting point.