Because I live on earth, where a gas or liquid filling vacuum or area of lower pressure decreases in pressure until it completely fills the area and meets itself trying to come back out. Oh, okay. Well, here on earth, let's say the atmosphere is about 30 km thick. Based on that, and the earth having a diameter of 12,750 km, the volume of the atmosphere is approximately 15,393,367,321,000,000,000 m3. When you open your vacuum tube, you're increasing the volume of the atmosphere by the volume of the tube, which, at 160,000 meters long, and let's say 20 meters wide, is a volume of 50,265,482 m3. Finally, since our opening is on top of Mt. Everest, the air up there will average around 228 mm Hg, or about 0.3 atmospheres.
Now you've got all the info you need to plug into P1V1 = P2V2, so why don't you solve for P2 and get back to me with the Earth's newly decreased air pressure, eh?
Big numbers, but no sense. The outside weather shows that air is elastic not solid. Movement is not instantaneous. Objects in motion and all of that. Your statement doesn't work on water (or hold it) let alone on air. Indeed, when you set off an explosion, it is followed by a vacuum. It doesn't just push out evenly in all directions dissipating to zero. Explosions are in fact a wonderful example of the kind of pressurization we're talking about.
Your instantaneously equalizing world simply doesn't exist.
Your theory would also lead one to believe that pouring a bucket of water into the ocean would instantly raise the worlds coastal waters a molecule or two.
But your numbers are nice.