You don't need to be that smart to read a wire ampacity chart. To be honest the DIY work I've seen on average is better than the professional work I've seen.
You're far more likely to burn the house down cooking dinner. Should we all hire professional chefs or eat out?
Am I mis remembering the fact that you install solar systems and the associated electrical connections for a living? If not, how would you react if someone contacted you for a quote, then they questioned your charge because they said you were not worth the labor charge you were charging, because anyone with an "average brain and 3 months" could do what you do (which is exactly what this OP said in this thread).