I did say at the beginning of that article that you should click on the above link before reading the article. Anyway, this is what the brother mentioned in the article:

One may also ask, what is the wisdom behind abrogating the recitation of a verse but upholding its injunction? (e.g. verse on stoning)

This is because the Sunnah is just like the Quran, both are revelations. The Sunnah is also the actual law, and this being a test to those who claim to believe in Allah: they must believe in the Sunnah too and that it takes place of the Quran in many areas. See this article for proof of following Sunnah.

http://www.load-islam.com/artical_de...tion=myarticle

This then proves the importance of the Sunnah, and how important it is in our religion. We can ask countlessly why the recitation was removed, and why the ruling remained - however, this is through the wisdom of Allah.