What you just described is a huge farce.
The unnaturally high liquidity being created by HFT is actually being supported by most of the exchanges (through kick-back fees) not because it makes it easier for investors to buy and sell shares, but because the HFT is hiding a huge market correction that has been happening since 2009.
While billions of dollars in shares are being passed along at high speed, the rate of decline on shares during a correction slows to a crawl because it is hiding investor sentiment beneath the high speed veil. Since you can make more money on a stock gaining (sky is the limit) over declining (zero is the bottom), almost all of the HFT is aimed at gains and not losses.
So, over the last five years, the HFTs have been pumping stock prices up while actual volume of trades HAS DECLINED.
Look at any graph of stock trade volume over the last 10 years. You will see a very steady downward trend on volume and an unnatural upward trend on stock prices.
http://finance.yahoo.com/echar...^DJI+Interactive#symbol=^DJI;range=5y (Hit Max)
You might also notice two huge days of volume on December 6th and 19th of 2013. If you can figure out what happened on those two days, you'll discover where your parent's retirement went.