One might argue that Touch ID is too strong to be used where there was no security before. In an arms race with thefts and hackers, leaping too far forwards might not be the best option in the long term.
Even if your phone was unlocked, they probably wouldn't bother more than a cursory glance. They have more phones to steal than to bother with is on some random person's phone. When the data is important, the theft will be more targeted.
I haven't heard of it recently, but a few years ago there was a story on phone operator temporary staff that would offer clients to move their contact info from their old phone to the new one (it's a completely legit service) and keep a backup of the old info to sell it. The price for an entry was something like 2 cents, but data would be sold by batches for about 700~800 dollars.
I didn't find any quick resources in english, just for the numbers there was this piece by trendmicro (to note, they are of course biased to make the number a littre bigger) http://blog.trendmicro.co.jp/archives/4828