Again, I do not consider this to be "functionality", but a bug. Spaces were and continue to be very much a pro feature which most common users do not understand. To shove it down everyone's throat when they think they are just making a window bigger is pretty bad UI. Notice the name of the feature is "full screen", not "new space that behaves different than every other space by being exclusive to one app". In fact, to higlight this, it sometimes doesnt even actually fullscreen! As with the new Messages app, it doesn't full screen the app but rather makes it take up roughly half the screen, surrounded by linen, in it's own space (all in single monitor mode btw). So if they want to have that silly button on the top right of the window, the maybe-fullscreen-maybe-not-but-for-sure-a-different-space button, then by all means. But dont make this the behavior of cmd-f which has meant something totally different for the last 10 years.
Because it's the platform default. That's how it should be.
> It provides zero functionality over "non-native" (??) fullscreen
Wrong. It puts you in another "Space".
You can argue that you like OS X's fullscreen feature, but VLC implements it just how it sould be.