contribute to society except for profit for themselves
Your opinion, fortunately we aren't slaves to one person's opinion as to what is valuable "to society". I am sure all the employees, their families, children, dogs, etc. of the HFTs, producers of all the networking and computing gear they use, the buildings and home they inhabit, the doctors they visit, and so on, might disagree with you about the lack of contribution to society.
That is a bad argument: People making money with organized crime spend money on employees, family and goods too, but that does not make it a good thing. If the HFT people would not be skimming billions of dollars from the market, millions of people might have received 100$ more since their pension fund would have done slightly better, and they would have spent it the same. What did the HFT contribute to society to rip off all those people?