> This is the one thing they do which helps, not hurts, human traders.

Providing liquidity is their job, and it benefits the market as a whole. If market making by HFTs is a good thing, it’s difficult to malign those same firms for, well, making markets.

> They rent satellites to count how many trucks leave factories.

This isn’t their business model in the slightest. Quant funds certainly do this, but HFTs look for alpha in market microstructure.

> They have access to person-to-person dark pool trades that never show up on the normal exchanges.

Institutional investors can use dark pools to minimize market impact when trade large blocks. HFTs don’t benefit from having limited information on these flows.

> Algorithmic trading is a secretive black box

Algorithmic trading != HFT in the same manner that a rectangle is not a square.

> It can scale up infinitely.

HFT strategies don’t scale. ‘Scalable’ strategies support a large amount of capital. HFTs run high sharpe, low capacity strategies.