I don't have any statistics but I have never seen a non-GM car with direct ignition have a coil pack go bad (and maybe only 2 old-technology ignition coils go bad - due to visibly cracked housings letting in moisture). I can't think of a reason why the new ones would last shorter unless underdesigned. Modern ignitions with or without distributors have a cleaner waveform which would put less stress on the coil, even though the voltage is higher.

A distributor ignition has one coil while the direct ignition has a coil pack - one for each cylinder. The presence or absence of a distributor would not likely affect coil life - the distributor itself is a more common cause of ignition troubles by far than the coil.

Was it verified that the coil pack was really defective and in what way?