This is another relic from the past, a past without central heat. Room temperature was once more like castle temperature - damp and in the low 60s if you were lucky. Today, room temperature generally means somewhere from 72 degrees Fahrenheit and up. That is not wine country.
At warm temperatures, wines begin to go out of balance. They show off their alcohol and tannin and loose the focus that their acids give them. If you want to get the most out of your wine, serving it cooler will always be better.
This, of course, is where things get a bit sticky. Wine geeks have a precise temperature for just about every wine, and a glass for each wine to boot. An easy rule of thumb for wine service is the 15-minute rule. Take your white wines out of the fridge 15 minutes before service and put your red wines in the fridge 15 minutes before service. It’s about as imprecise as you can get, but that’s what general rules are for!