Because that in itself would be a huge project, with moving targets as the source projects develop over time. If it were that easy the VLC people would just implement everything themselves and not need either library.
> I never understood the OSS communities. It just seems simple to me. If you don't like it, fork it and do your own.
The problem is, of course, the humans.
People sometimes take things very personally even when not meant that way. A significant fork for no good reason can distract from the work of the core project and dilute the user-base, and people will not always agree on what a good reason is/n't. Sometimes the problem is stated as poor code and/or procedure quality, and this can be taken as a rather direct insult.
Sometimes massive forks happen because of differing priorities between different groups of people and everything is perfectly amicable - you don't hear about these cases much (unless it inconveniences the userbase) because there is no drama to make a noise about. Sometimes these forks later re-merge, sometimes one becomes clearly superior and the other fades out, sometimes they go on to be completely separate projects.
It sounds like three are personal issues involved in this particular mess that we don't exactly know about so can#t hope to fully understand because the discussions started in private and have not been published and as we all know any argument, especially one that has gone on for some time, people can lose track of the true chronology of the issue and that can make reconciliation near impossible.