From a New Yorker article:
To be sure, there are mental disorders in which we know enough of the vectors to say that people who have them should not occupy certain positions. A person prone to delusions should probably not fly an airplane, and a pedophile should not teach children. But these are the exceptions rather than the rule. From all we know so far about Lubitz, he was not one of those severe cases but rather someone who was among the millions of people who once contemplated suicide and was being treated for a mood disorder.
Could we drop the before "exceptions":
But these are exceptions rather than the rule.
It seemed to me that the use of the here indicates that the author believes the two mentioned exceptions to be the only exceptions. In line with this reasoning, if we drop the, it would mean that there might be further exceptions, beyond the two mentioned. There must be something wrong with this reasoning, since the author is a native speaker and he must've used the article properly.
P.S. What I mean is that we don't use the here:
(At a market stall) "I want to buy something from you, and you have a nice choice of fruit here. Just look at these beauties! But these are apples rather than oranges, and I want oranges." (we don't say "but these are the apples)