To answer your first "Why?" it's because employees have to be paid much more when working over 40 hours / week. Drivers will no longer be able to work an extra 5 hours when they need extra money: They'll have to have a second job. Similarly, there are certain minimum costs associated with each employee above and beyond the costs of a contractor. This may mean Uber is forced to favor drivers who commit to a certain minimum of hours per week, ridding themselves of the "before and after work" driver crowd. The net effect of these two forces means Uber will just be another part-to-full-time job.