The only problem with that Spex, is that a poorly placed Chorus Fruit snack could leave them trapped up there with nothing to do but starve if they didn't bring portal supplies. I think that qualifies as mildly game-breaking.
As a side note that last screen shot was taken after standing in place with the bug active, and entering the video settings and turning the VBO's off (checking again with no change in the bug) and then back on and taking the last shot.
The problem is probably that your computer can't handle your current settings. Try turning your graphics to "Fast", render distance down to 6 or so, and your smooth lighting off. This is 100% "your computer can't handle the game" errors, and is not a bug in the game.
That would probably work for now. Thank you for the tip No Way.
It's still in the 14w11b snapshot as well. It makes it impossible to place single standing dispensers in the correct orientation.
Entering the End without supplies is not game-breaking because it's something you're supposed to be able to do, and therefore you're required to deal with the consequences of your actions (aka a painful death). Using a Chorus Fruit to get on top of the Nether, however, is not. There has never supposed to have been a way to get onto the roof of the Nether, and with the way this bug works, some unlucky player could accidentally get stuck up there and therefore lose every item they have on their person. Granted it's not likely, and some players would enjoy the ability to get on the Nether's roof, this is not something that Mojang intended and therefore either needs to be fixed, or at least modified to make it less game-breaking should you get stuck up there.