Presumably because they made more money from LBA than EMA...why else do airlines choose to fly from one place in preference to another. Nice to see that the COO has "forgotten" that they started from LBA flying to Rome so that would make NAP their 2nd Italian destination flown from LBA...
Great picture of an (obsolete) Monarch AB6 at the top of the article.
Of course the real reason the airline (in fact any airline) operates is because they expect to make money - and generally, smaller regional airports, because of less competition, ought, on paper to provide a better return than fighting for market share at major airports such as LGW / MAN / EMA (for bucket and spade business) and BHX.
Am I a cynic or what?