Its all about the mindset of people who uses bitcoin. If only bitcoin will be used in a positive way. Since bitcoin doesn't need personal meet ups or face to face transactions, it will indeed help to lessen the rate of theft. Especially in the for of cash transactions.
of course not all transaction are positive and not all users gonna use bitcoin in a positive ways there are always ups and downs even in the most perfect system there is, there will always be a human error, and in my opinion bitcoin would not count as a theft lessen transaction because even escrows would do such crime!