So why do you need a wine refrigerator. Well if you are just drinking your everyday wines that you get form your local supermarket and you drink relatively quickly you probably dont. But when you start to get serious about your wines and start buying the more expensive bottles that you keep longer the temperature that you keep them at becomes more important. No one wants to spend $50 or $100 on a bottle of wine to find it has gone bad or lost its best flavors because it wasnt kept at the ideal temperature.
The other reason is once you start drinking more wine, you will find it will take up a lot of room in your normal refrigerator. Having a seperate place to store your wine will allow it to keep better and wont get in the way. The normal home fridge is constantly being opened and closed which is also not an ideal environment for storing good wine that you want to stay at a certain temperature.