I am not saying HFTs can't sell but there should be penalty for higher frequency. It means they have to craft algorithms which will take longer term view of stocks (and their fundamentals) rather than ignorance of other participants
Market makers make fractions of a percent per trade. How will your "penalty for higher frequency" deter traders that prey on "ignorance of other participants" or whatever, but don't put market makers out of business?
Easy, bye market makers! It's like a layoff, some good will end up getting culled with the bad.
Unfortunately, if you don't have people to make a market, it's not going to be a very good market for a bunch of important values of good.