The concept behind the Pacifica seems to have been a vehicle blending characteristics of a station wagon ("break" in England and other places) and a crossover sport-utility (SUV). The emphasis was closer to the station wagon than the SUV. In other words, the Pacifica was a wide station wagon with slightly higher roofline than a conventional sedan or wagon. A crossover SUV is also essentially a station wagon, but it has a tall cabin and usually sits higher off the ground than a Pacifica.
When they first appeared, Pacificas were surprising due to their comparative bulk. They weren't ugly, so their disappointing sales level was due to other factors including unreliability (see the above link for more on this). To me, its defects included its size -- large for a car, but with little more carrying capacity than a station wagon. Besides, station wagons were becoming a rare species in the American market thanks to the advent of the SUV and its tamer crossover variation. If a buyer's need is carrying a lot of bulky stuff, then a SUV makes more sense than any kind of station wagon.
It is interesting that Toyota introduced its Venza, a Pacifica-like vehicle, right after the Pacifica's demise.
The background looks a lot like California's Malibu.
This offers a sense of the vehicle's bulk.
The Venza is Toyota's version of the Pacifica.
The Edge is less sedan-like than the Pacifica and Venza, though it was based on the Mazda 6 platform. What it shares with the others is a chubby body. Unlike the Pacifica, it was successful in the marketplace.