Because, you know, those “evil features” like the bullet-buttons that are so popular with hooligans.
On the West Coast, gun owners in California will face new restrictions after Gov. Jerry Brown signed a law banning the purchase of semiautomatic rifles with so-called “evil features…. [that] include pistol grips, flash hiders and bullet-buttons that make it easier to remove and replace (already modified) ammunition magazines. The Los Angeles Times reported an increase in gun purchases in the lead-up to the Jan. 1 implementation.
Source: Fox News