If people continue to seek a relationship through cyber space, eventually you'll become that person you personally created and have false sense of place. Especially if your only source to 'getting' some is through the internet. Your original 'game' will slowly disappear. I'll admit, I tried it a few times and they turned out ok, but the real thrill in anybody should be going out and achieving it, first hand. Thus improving your confidence so you'll be ready for future experiences/events.
ETA: Also, the continuous use of online dating could later create a high sense of insecurity. Due to the fact that you're constantly having to use the internet for help/guidance. When faced with a real women in a real life situation, you won't have your notes in your face for assistance. How would someone react in that situation, then?