Just as a frumpy recluse can’t convincingly impersonate a fashionable social butterfly (at least not for an appreciable length of time), neither can most beer styles gracefully rock oxidation. It takes a certain _je ne sais quoi _to become increasingly refined with age. A beer either has it, or it doesn't (and those that do, I affectionately refer to as my Sophia Loren beers).
The Beer Judge Certification Program (BJCP) describes oxidized beer as demonstrating “Any one or a combination of stale, winy/vinous, cardboard, papery, or sherry-like aromas and flavors.” I would venture to say that most of us have no desire to taste cardboard or paper, unless we are goats. But wine and sherry? I wouldn't turn that down.
Most of the time, though, when we speak of oxidation, it’s undesirable. Oxygen has a way of destroying the things we love, pulmonary alveoli notably excluded. Think of freshly cut apples or avocados. Leave them exposed to air, and the effects of oxidation become visually apparent as browning sets in. The same thing happens to beer. Oxygen exposure degrades lively alcohols and aromatics into bland shells of their former selves. In most cases, drinking oxidized beer is not an experience one willingly seeks.