Viewing LA Logs via Azure Monitor

Why can you not always view all the logs for certain Azure Resources via Azure Monitor Logs ?

For example, if I go to Log Analytics / Logs and run the following:

ADFActivityRun

then I get all the latest ADF activity runs as expected.

If I got to Azure Monitor / Logs and set the scope to an ADF Instance and try 

ADFActivityRun

then I just get the failed to resolve table or column scalar expression.

It's not just limited to ADF, there are other resources (AKS for example) that exhibit this behaviour as well.