The difference is that Uber is disrupting a service/industry that is only non-competitive because of monopoly style regulatory capture. That is anti-capitalist and therefore ripe for displacement (and subsequent cheering). A typical employee cab driver still has the option to drive for Uber. It's the 'badge' holders and dispatch companies that are being hard hit, because they were protected from competition for so long by being able to buy up the limited number of taxi licenses that were made available in a given area.
Whereas there IT workers being displaced is happening for the opposite reason. Ie. H1-B regulations are allowing employers (monied interests) to bring in temporary cheap labor thus driving down the value of the resource in a smaller segment without affecting the value of the economy as a whole.
If either workers were required to have some kind of permanent residency (or be aiming towards it - i.e. immigrants), or if there were absolutely no restrictions on workers or immigration, then the system would be pure capitalist. However, in that case, the whole economy would be affected equally, and the cost of living would drop (or the dollar would drop), thus equalising/buffering the effect. That would effectively remove any benefit to the corporation from the above behaviour, thus curtailing the behaviour in a natural capitalistic way.
So, no, this is not capitalism working. If anything, it is 'corporatism' working.