Scalping is a risky strategy, although it is a profitable strategy for short-term rewards. Traders need to be quick and have a strong trading psychology to become a profitable scalper.
I guess it is considered that way due to the high frequency nature of it, low risk to rewards and requirement for high strike rate.
Scalping traders maybe can make a big accumulation profit from many trades they made, but also need to accompanied with risk-reward ratio to keep small drawdown, will vain able accumulate big profit but one-time loss make all profit vanish.
I scalp daily, the big lesson learned is don't scalp choppy days like today, I lost $400 today scalping .... I have to be more disciplined re overtrading