I agree.
There is a common theme most employment lawyers will tell you when it comes to company policies. If you make an exception for one, you open the door to do the same for all.
Now, I don't know all the specifics in this case, but am quite familiar with UPS, since I worked for a company that provided onsite medical services at one of their major hubs years ago.
From my experience, UPS is very proactive when it comes to making sure drivers are healthy, able to perform the duties of their job and they provided education, onsite training, rehab and light duty for those who required it, when light duty was available.
Now, this is where I have questions. Any company, does not have an unlimited amount of light duty available at any given time, just as they have a limited amount of jobs to offer. The question may become, should the company be forced to offer an unlimited amount of light duty jobs at any given time, or would this be considered a undue burden on the business?