Essentially.. it's there to make linkspamming and other automated bot-like marketing more difficult. Also, there are some really useful perks, like giving Reputation to those who have read (or at least visited) the manual pages.
First 1000 or so points are quite easy to get. It takes some time and effort, but nothing too serious.
Agreed, the first 1000 you going to get if you want to learn Construct 2 just by learning, and therby opens doors to the forum and other perks like pm etc