so this copilot is a complete scumbag
You do not know enough to conclude this.
How often do suicidal bus drivers drive off a cliff? Suicidal operators of huge industrial machines take down their workplace? Pretty rare, even if there are hundreds of times as many bus drivers / heavy machine operators as compared to airline pilots.
Many countries have zero effective regulation on bus driver / machine operators sleep cycles. Lots of drivers / operators work without any social interaction which could have helped detect and even prevent suicidal tendencies. This pilot was at least working along with another human being. Was in Europe - which at least on paper had good sleep cycle regulations, and knowing Europe, regulations would have had some force of effect too.
There could have been other reasons for this event. Your ignorance of them do not make those reasons stop existing.