Hey phred, I don't know what your friends expected in Marseille but it's one of my favorite French cities. In fact, Anthony Bourdain just listed it it as his favorite! Walking along Vieux Port at different times of day is always an adventure from the fish mongers with the morning catch to lovers strolling at night. The city is a melting pot of all the countries on the Mediterranean. A magnificent cathedral overlooking the city, a classic mix of cultures, excellent restaurants, local artisans, good museums, Chateau d'If and the calanques. Yes the city is gritty, but to me it adds to the charm. Though I only flew out of the airport once, it was easy to get to and simple to find my flight. To me any airport is no more than an inconvenience to be borne by travelers, not a tourist attraction in itself.
Sort of reminds me of the Bronx where I was born. Marseille, though the second largest city in France, gets little respect and is joked about, reviled by Parisians and condemned by the ignorant. Yup, it's the Bronx of France. I can hardly wait to go back.