Using "aether" as a generalized snarl word is really irksome. None of us were alive for the debates in physics of a century ago. General relativity is an aether theory; i.e., it ascribes properties (the metric tensor) to empty space. Appeal to authority below since that's the level we're playing on when we misuse dated terminology like this.

"We may say that according to the general theory of relativity space is endowed with physical qualities; in this sense, therefore, there exists an ether. According to the general theory of relativity space without ether is unthinkable; for in such space there not only would be no propagation of light, but also no possibility of existence for standards of space and time (measuring-rods and clocks), nor therefore any space-time intervals in the physical sense."

-- Albert Einstein

When most people talk about "aether" they seem to mean the "luminiferous aether" which propagated light waves like water propagates water waves. The problem with that theory was demonstrated by the Michelson-Morley experiment: The speed of light does not change regardless of how you move relative to the light source. Light can't be a wave like water waves are. The luminiferous aether is therefore disproven.

Applying the term "aether" to other theories is uncommon, especially among non-physicists.