You can read Robs explanation here yourselves.
What he seems to be saying is that his primary motivation for supporting SCO is a dislike of Linux supporters who attacked one of his articles written at about the same time as the SCO saga kicked off. Despite having some doubts about SCOs claims he felt he needed to stick up for them because on the one hand he though Linux supporters were a bunch of criminals and on the other he thought Groklaw was misleading people and misrepresenting the facts surrounding the case.
Whats missing from the article is any apology at all from Mr Enderle for failing to research his subject and calling the result so wrongly or any apology to Groklaw who were clearly not misrepresenting anything and predicted the actual result of the case perfectly."
Link to Original Source