Yes indeed someone if they really wanted to can steal your money with your bank account and routing number.
That is if you happen to give your bank account and routing number to someone who you do not trust or a company that was not trusted.
But in reality we always give out our routing number and bank account number when we write and send checks as the routing number and check number are clearly marked on the bottom of the check.
So if someone wanted to debit your checking account for money to steal it then they could if they had a way to make the transaction which is easy for anyone to do.
But it's very rare someone will steal money from your bank account using the bank account number and routing number but the possibility is there.