theres only so many man hours and materials in any specific job and its not rocket science to get a decent finish on anything especially for those pretending to be qualified at that trade.
im a joiner to trade and I did spraying on my celica cosworth . it was just as good and long lasting as the bodyshops efforts with no orange peel effect etc in the pearlescent blue paint. its not hard so theres no excuse .
unfortunately the car didn't last as long as the paint job would have