If the government really wanted to protect us from ourselves they would limit gambling, which costs poor people a lot and is known to result in unfavorable odds, and they would discontinue the lottery. Instead because the lottery and gambling make the government and big institutions money they are legal. Restricting pattern day trading is, likewise, an attempt to give those with money more leverage over those without money. This law is directly discriminates against those without money and it was passed by those with money. The government has essentially passed two sets of laws, one for the rich and one for the poor. These laws were undemocratically passed by the rich for the rich under the false pretense of protecting the poor. Such is a hallmark of an aristocracy. No nation should have a different set of laws for the rich than for the poor.
The entire WIkipedia article, especially all the criticisms, are worth reading
https://en.wikipedia.org/wiki/Pattern_day_trader [wikipedia.org]