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.

Basically you're arguing that the race to the bottoms is good for everyone involved.

From a country that has hard fought-for USD16/hour minimum wage, paid 10 sick leave and 20 annual leave days per year, this doesn't appear true at all.

How does allowing flexible work arrangement imply “race to the bottom”?

Nothing precludes proper employees with flexible arrangements. Forfeiting overtime pay and other labor protections afforded by law are definitely race-to-the-bottomy.

Nothing precludes contractors having labor protections either.

What a tasteless and tortured analogy. I'm sure the slaves hated being freed as much as my brother will be when they tell him that he needs to drive X minimum hours a week to keep his employment status with Uber/Lyft. More realistically, there probably won't be an Uber/Lyft left to drive for if this ruling sticks. God knows they're already bleeding funds as we speak. There's no way they'll stay afloat.

No matter how you want to spin this, it's not going to be a victory for the majority of the drivers. Let us, in our high and mighty chair, obliterate a burgeoning industry filled with people voluntarily making money on their own time. Let the taxi medallions flow back in its stead. Problem solved - slavery is no more.

Freed Russian serfs were indeed distressed in many cases, which doesn't make their emancipation any less moral.

Uber pays less than minimum wage for many, which can't stand.