Bitcoin can be tracked and a government could mandate that the bitcoins you use to buy a house be from the "legitimate" subset of bitcoins. With Monero, you can earn money from selling weed and turn around and buy a car with the exact same coins. Nobody can even ask you to prove where they came from, short of declaring them as income, (as with cash) but that becomes much harder when you can just fly to France, buy a house there (the government doesn't care if you paid taxes for that money in another country), and fly back.