If it turned out that the physics behind standard cosmology were backwards, being mathematical accurate would in retrospect be pointless. Get the physics and interpretations right first, and the math will follow, not the other way around; as could be interpreted from current theoretical astronomy and the resulting standard cosmology. To be direct; most of the explanations of cosmic dynamics are derived from math. And current theories predict little.
One point EU makes, is that according to deep field Hubble observations and the various redshift mechanisms, one can assume a universe of unknown age and unknown extent. Explaining origins (as creationists would) is seen as rather pretentious, as our ignorance is so profund that we can't even ask the right questions in cosmology. It must also be added that there is no creationist aspects of the Electric Universe, and there are no theist pronouncements among the advocates. (The somewhat similar Steady State model was once loosly associated with atheism, since there was no proposed point of creation).
Having said that, is there no math behind electricity, magnetism and plasma physics? Is it less advanced than gravity formulas...?