It's all a matter of percentages. If you put 100 helicopter pilots in a room, then about 90 of them will be ex-mil and 10 will be ex-civilian (give or take, YMMV). Of those, if 10% are the proverbial "bad apples," then one civilian guy will stink while nine of the ex-mils will qualify, thereby giving an erroneous impression that there are more "bad" ex-mil guys than civilian.
Let us acknowledge that the military provides better training and discipline. What the individual pilot does with this is pretty much up to him/her, and a lot depends on the talent of that particular person.