Just the way CK happens to do it. Sorry there isn't a better answer haha
The scores and how CK presents information are two entirely different things. Be careful relying on what CK provides and definitely read up on how credit is assessed and the typical weights of the usual factors. A CO is definitely a derog. It will have a significant scoring impact and it will be a red flag to creditors. You definitely want to remove all derogs that can be removed. Carefully research in the Rebuilding subforum.
Another example with CK is AAoA. CK only considers open accounts which is really AAoOA. FICO models and most creditors use AAoA which includes closed accounts on your report.
Don't just rely on FAKO and FICO. Always consider the specific scoring model & CRA when referencing any score and consider the relevance of the model & CRA combo to agiven product. There are creditors that use VantageScores. There are creditors that do not use a FICO. Even with the creditors that use FICO's they do not all use the same model and the specific model will have an impact on the number generated.
Different models evaluate report data differently and can have different scoring ranges. You cannot use a score generated by one model to determine a score generated by a different model. If you want to know what a given score is then pull that specific model & CRA.