Scalping is not easy to pull off profitably in the long run for vast majority of the people.

Only a very small number of people can do this, but the ones who are skillfull can make a load of money if the broker allows this to those few who are successfull and it would eat it into their bottom line.

1 Pip spread is a ploy to get customers in this very competetive forex market. If you are a good trader, a difference of a few pips will not have a significant effect on the perfomance of your trading in the long run.