Problem with fatigue, it's often confused with being tired...one can have a reasonable nights sleep, and still be suffering from the cumulative effects of fatigue...it's a bit like hypoxia, one doesn't realise it at the onset...but the performance level drops appreciably
I certainly agree that there is no excuse for not having vertical guidance on any approach in this age of GPS...with all the facilities available it's just plain wrong to be flying outdated non-precision approaches with the exception of severe terrain issues...