The minute I decided to write this post, I knew that the title alone might unleash a firestorm the likes of which this blog has not seen before. Wine drinkers are a passionate lot, and there are very strong opinions when it comes to what makes a good wine. I'll save you all a little suspense and say from the outset that I don't think that varietal correctness ALWAYS matters in every situation, but let me explain myself before you throw any large stones in my general direction.
For the serious wine connoisseur, or for professional critics, varietal correctness is very important. When you are evaluating a Cabernet Sauvignon, you expect it to have the color, nose, and palate of a Cab. Regardless of whether you enjoy the taste of the wine, if it doesn't match up with what you expect from the varietal, you can't really call it a "good" Cabernet. Even for a casual wine drinker, it can be pretty disappointing when you buy a wine expecting one thing and end up with something entirely different. From the perspective of a person evaluating wine, varietal correctness always matters, and is a significant factor in determining the quality of the wine.
A complicating element can be where terroir ends and typicity starts to come into play. Some wines have famously different expressions of the same variety, such as the difference between a Marlborough Savignon Blanc and a French Sancerre, or a California Chardonnay and a Chablis. Over time a lexicon of the characteristics of these wines has developed, and is somewhat in flux as new location gain caché, but still there is general agreement about what constitutes a varietally correct version of these wines. Living in a still maturing wine region here in Texas, I sometimes hear deviations on standard characteristics ascribed to terroir, where it might be more correctly described as a wine devoid of true varietal expression. The line can be a fuzzy one.
All of that being said, the average consumer doesn't necessarily have any idea what the varietal characteristics of a given wine are, so they don't really care whether their Sangiovese tastes like a "typical" Sangiovese, as long as they enjoy the experience of drinking the wine. When I have shared a new wine variety with friends over dinner, they only know whether they like the wine or not, and generally poo-poo any comments that I make regarding the typicity of the wine. Though I'm venturing into the now clichéd every-man territory that us bloggers are becoming famous (or infamous) for, my friends might find it mildly interesting (and even that is a stretch sometimes) to know whether the wine is typical for the variety, but ultimately they only care how the wine tastes. Clichéd though it may be, ultimately the only good wine for you is the one that you enjoy.
As a person who writes about wine, it is important to me whether a wine is typical. As a wine drinker, I can say that I have had wines that I was able to enjoy drinking that weren't really good examples of what their variety should taste or smell like. My evaluation of wine will always include evaluating whether the wine has the characteristics that a good example of that variety should, but I also try to keep in mind whether a person who has no basis of comparison for the variety is likely to enjoy the wine. To sum it all up, just because I don't find the Sangiovese from earlier to be typical doesn't necessarily make it a bad wine, but it might just make it a bad Sangiovese.