Reviewers reject some wines as faulty and merely dislike others, and readers often cannot tell which is happening. The distinction rests on whether a specific identifiable cause is present.
Faults have named causes
Cork taint arises from specific compounds that suppress aroma and add a damp cardboard character. It is detectable, attributable to a known source and not a matter of taste.
Volatile acidity above a certain level, excessive oxidation and microbial spoilage each have identifiable chemical signatures and known origins. A laboratory can confirm all three without tasting the wine.
Because the causes are known, faults can in principle be measured rather than argued about. That is what separates them from stylistic complaints.
Thresholds complicate the picture
Most fault compounds are present in all wine at low levels and only become problems above a certain concentration. The threshold is not a sharp line.
Small quantities of volatile acidity add lift and complexity, and many admired wines carry more of it than a technical standard would permit.
Sensitivity varies between tasters, so a level that ruins a wine for one person is invisible to another. Disagreement about faults is therefore genuine rather than careless.
Reduction is the common misdiagnosis
Sulphur compounds formed in the absence of oxygen produce struck-match or rubber aromas that many tasters read immediately as a fault. Some of those compounds are genuinely unpleasant and some are not.
Much of it dissipates with air, which means a wine dismissed on opening may be entirely sound twenty minutes later. Vigorous decanting resolves a large share of these cases.
Some producers cultivate a degree of reduction deliberately for its effect on texture and freshness, which puts it squarely in the contested zone.
Preferences masquerade as standards
Complaints about too much oak, excessive ripeness or insufficient concentration describe stylistic positions rather than defects.
These are legitimate assessments and should be stated as such, since a reader may hold the opposite preference and want the wine.
Framing a stylistic dislike as a fault removes the reader's ability to disagree usefully, which defeats the purpose of the review.
What a useful review does with both
Faults are reported as observations with the specific character named, so a reader can judge whether the bottle was representative.
Preferences are reported alongside the reviewer's known position, so a reader can adjust for it in either direction.
The test of a review is whether someone who disagrees with the reviewer's taste can still use it to make a decision.