Wow, that's really unfortunate that it doesn't get to 60 in second gear. For as much as I despise the garbage can Aisin 6-speed in the Five Hundred (its the main reason I'm getting rid of an otherwise good car), its geared pretty much perfectly, with 60mph hitting just before the shift into 3rd, where the car then kind of bogs down a little, as 3rd gear starts the more econo-mode taller gearing (there's no 1:1, but rather there are two overdrive ratios)
I'd venture to guess that if the first two gears were just a shade taller, like in the Five Hundred (they're only just taller than the FuSpo), the car would have a much more respectable 0-60, if it could hit 60 in 2nd, or if 3rd were shorter. I'm kind of surprised at just how short the first two ratios are after looking them up, considering the power and especially the torque the engine is making. Those short gears don't give it a chance to build up some more considerable forward momentum before bogging it down, even more so considering the reported heft of the car. The gearing has physics working against more spirited acceleration (times), and I'm guessing its a rather large factor in the 0-60 gripes.
This is just the assumption I would make based on my couple years of mechanical engineering before architecture. There may very well be more factors in this mix.