Many view it in far more simple terms, it just means that for some aspects the results can't be known in observation.
It's quantum uncertainty principle, the who 'does it exist' thing is a extension into philosophy with no real base.
"This ascribes the uncertainty in the measurable quantities to the jolt-like disturbance triggered by the act of observation. Though widely repeated in textbooks, this physical argument is now known to be fundamentally misleading.
While the act of measurement does lead to uncertainty, the loss of precision is less than that predicted by Heisenberg's argument; the formal mathematical result remains valid, however."
From Einstein.
"the problems inherent to the uncertainly principle lay in the measuring not in the "uncertainty" of physics" - puts it well.
Or from Feynman,
"In the beginning of the history of experimental observation, or any other kind of observation on scientific things, it is intuition, which is really based on simple experience with everyday objects, that suggests reasonable explanations for things. But as we try to widen and make more consistent our description of what we see, as it gets wider and wider and we see a greater range of phenomena, the explanations become what we call laws instead of simple explanations. One odd characteristic is that they often seem to become more and more unreasonable and more and more intuitively far from obvious. To take an example, in the relativity theory the proposition is that if you think two things occur at the same time that is just your opinion, someone else could conclude that of those events one was before the other, and that therefore simultaneity is merely a subjective impression."
http://www.informationphilosopher.com/solutions/scientists/feynman/probability_and_uncertainty.html