Here's the big thing: Most people aren't on the economic top and never will be, so it's in most people's interest to get the people on the top to give up some of their cake. It's funny that most of the best places to live have progressive taxation.
That would be a huge thing, but it isn't true. This mistake even has a name within the field of economics, the zero-sum fallacy. In fact, if I thought that you were right about this then I would be against any free-market, since this would imply that anyone who acquires any wealth can do so only at the expense of someone else i.e. profits would be theft. However, the zero-sum fallacy is just that, a fallacy. Indeed, life on earth would be impossible if it wasn't a fallacy, and so I have no problem with profits, since they add to the total wealth available without taking anything from anyone. The idea that the wealth of the lowest earners can only increase if we steal and share out the wealth of the highest earners is simply false, and there is a huge body of literature on the matter for anyone interested in finding out more.
Edit: On another note, many people who are the lowest earners today will be higher earners before they retire. It is no coincidence that those in the lowest income brackets also tend to be young people who have only just started or have yet to begin their careers. The "classes" are not static and their members are continually changing, as should be expected be in a free economy with or without "progressive taxation" (infact, I would expect less movement between "classes" in places where there is "progressive taxation", since people who are given something for nothing will have little incentive to invest the time and effort to become a bigger earner, and "progressive taxation" has a nasty habit creating a dependent underclass, despite the intentions of those who advocate it).
In any case, the term "progressive taxation" assumes that which is under debate i.e. whether there is any progress made through "progressive taxation". Most of the time, I think not. In fact, half of that which passes for "progressive taxation" seems to me to be anything but, often a transfer of wealth away from those who have least to those who have the most, since it is the latter who successfully pull the right political levers to get their way.