Racism isn't an implicit call to violence. Violence is one of the ways it can manifest if it's deranged enough, but most racism is just sorta quiet and often unconscious.
It's not a good idea for the government tell you what you're allowed to say - that change has to come naturally from the bottom up, not artificially from the top down
It's also enabled everyone to see cultures and ways of life they would never be able to before. People can share their differences and traditions more openly too. Knowing more about cultures, practices and different people is what opens doors to not being racist