"But what if you were one of the people selling to Charlie. Before HFTs made the price faster you were the one getting screwed!"
The sellers sell at their ask price (or at my bid), it's their decision to sell. If you offer to sell something to me at $10, I haven't "screwed" you just because someone else was willing to pay $11.
It absolutely is front running. Moving the price of a stock to your advantage because you know my intentions is exactly what front running is.