I don't know German air force policy during the early part of the war but perhaps fighter pilots were discouraged from attacking ground targets since their mission was to protect the Stukas and Bombers from fighter attack.
Also Blitz tactics worked so well the first part of the war it would hard to change the air force leaders mind set to a new way of doing things until things started going bad for Germany. In the early Blitz the Stukas were to act as airborne artillery and the fighters were to protect them during the attacks on ground targets. If you were an underling on the air force staff in 1941 and told the higher ups to drop the Stuka for more fighters your career would be over. I know TA Gardner would have no fear telling people his opinion but then he plays with concrete blocks all day.
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PS After re reading TAG's first post I see it was Hiltler who orders a change to fighter and fighter bomber prodution. That puts a damper on all the above except for Terry and his blocks !