Yes they can, there is nothing preventing them creating the package. But it shouldn't be a primary way of installing package. If you really need bleeding edge for development you can build it yourself.
A regular desktop user does not want bleeding-edge software; he will do just fine with last year's VLC. (A notable exception being the web browser.)
The priority for a regular desktop user is a nicely integrated system, and that is something that ISVs cannot deliver because they don't know what to integrate with.
Which is exactly why I've given up on desktop Unix. With Windows, instead of having to wait for the maintainers to declare a package worthy of their distribution, I can just run the vendor's installer, without any fuss or hassle. FreeBSD, IMO, gets packaging the most correct with separating user packages from the core distribution, but there are still times when they'll have an old version as well. Relying on a single app provider, be it apple or debian, is just silly.
It's about trade-offs. There's no magic bullet (surprise!).
For example, some folks hate the Windows way because it has drawbacks like a different installation look/feel/process for each application, there's no automatic updates (unless the application has it built-in, which most don't), there's no automatic dependencies (so each app installer has to bundle its own versions of things, which also don't auto-update), there's no single place to go to look for a program that does something you need, automated installations are hard, inconsistent, or non-existent, security issues are harder to deal with (some image library issues from many years ago are probably still in the wild, bundled into some old version of some application), ...
Please keep in mind that "just silly" is just perspective and priorities.
I still recall Microsoft finding some bug in their visual-c++ set of dlls. Problem was that just about nay software shipped with their own bundle of those dlls.
So All MS could do was to release a scanner to look for faulty versions, and beg people to pester ISVs about getting updates.