Daytraders using etrade.com are not even competitors to large firms who spend tens of millions of dollars setting up expensive equipment inside the NYSE datacenters that operate at the millisecond level.

I think his premise is that people are mad because they can't compete because they don't have the resources (money) to do so. If they were able to execute trades as fast as the big guys, they would be perfectly fine with the practice continuing. Since they don't have the cash to compete they are upset because they see someone else making money where they cannot.

So you (or parent comment) is saying somebody with limited resources can't effectively compete with huge corporation with resources several orders of magnitude bigger - and somehow this is unfair?

I imagine anybody owning a bike should be able to compete with UPS in delivering packages, and the fact that UPS owns a fleet of trucks, planes, warehouses and complicated logistics software just makes it all unfair. If only one would be allowed fairly competing with UPS by having them deliver packages as slowly as single guy on a bike, or alternatively if the government would create a bike that could fly like a jet plane - that would be fair.

I imagine one guy with a saw should be able to fairly compete with a logging company, and one guy with a bucket and trowel should be able to compete with construction corporation, and one guy with a screwdriver should be competing with Boeing and Lockheed Martin.

When that happens, I think we could take comparing a guy using etrade.com from his macbook with trading division of JPMorgan Chase. Until then - yes, they're playing in different leagues, as it always is in the world. There's nothing unfair about it.