Ford did it (decision to make ABS and side bags optional) purely for cost reasons....Fusion was brand new and since Ford was pretty much in the crapper during that time frame, they needed a "hook" to get people in the door to at least look at it and sit in it. By making those two items optional, they were able to lower the advertised price of the car to compete with Hyundai et al...in 2007, both items became standard equipment.
I also remember that when I picked up my car, Ford had just 2 days prior announced the increase in powertrain coverage...and my Fusion got a "free" bump in warranty...not that I ever used it....this car has been without a doubt the most reliable car I have yet to own as I roll past 115K miles on her.
Note to Ford: whenever you want to bring my Fusion "home" and do a Ecoboost style teardown to prove reliability, you can come and get my Fusion...as long as you bring me a replacement 2011 Fusion as compensation <hint hint :shades: >