There is some science behind wine tasting, when objective observations are made regarding a wine's alcohol, sugar, acid, dry extract levels - but what really gets written down and talked about...well that's something very different.
When you read a wine critic's views on a wine, you tend to follow someone you like - who tells it as you like it. Not sure this is objective, but it works for most of us. When tasting in a group there are many variables that get us talking - temperature being just one. Wine served too chilled is worrying - what are they trying to hide? Wine served too warm can be soo disappointing - Oh! and plain wrong. Temperature isn't the wines' fault!!!
I love the term 'dead soldier' when referring to wines at wine tastings. Drinkability should have a strong link to what's popular, and surely the first bottle finished (dead soldier) at a tasting is popular. So a combination of traditional scoring & drinkability is how best to judge wines.
Wine critics' taste large numbers of wines at one time. Scoring, marks, codes are needed to catalogue and remember what you've tasted. There are many ways of scoring - some score out of 100, very American and can be confusing. Janice Robinson scores out of 20 - reckoning that most wines score between 15 and 18.5, but variables creep in?? When given the price we are all hugely influenced as to what we expect - is that fair? Well I expect more from a wine costing £30 a bottle, than I do from a bottle costing £6!
Robert Parker, probably the best known wine critic came up with point scoring for wine in the 1980's, many adopted this approach. Wine Spectator's format of 100-Point Scale is widely quoted, wines achieving 90+ are boasted about - non-achieving wines of 75 or lower are not talked about. Simple? Maybe, maybe not - it's again subjective to that person's palate, or perhaps your palate. Different critics will all score differently for the same wine - so beware, the system is merely a good guide. The system really is designed to judge that the wine is typical for it's region & style.
winefolly.com suggest a good comparison : At a Dog Show, the winning dog is the one that most typifies the breed. If a dog has unique markings or funny legs not typical for the breed, it won't be rated as highly.
Remember that you only really see wines rated 85+ on the shelve, any lower and it's not talked about. But - you might really like that wine. Once again - it all comes back to opening that bottle and tasting it for yourself.