Copying a key takes 2 seconds and costs less than a dollar. Giving your keys to someone is a huge security risk.
1. Wander around the store finding someone who looks like they know how to copy a key
2. Follow them awkwardly while they finish helping someone else
3. Watch them wander through all the key templates to find the right one.
4. 20 seconds into the first attempt he notices a deformity and starts over.
5. 11 seconds into the second attempt, the key catches and goes soaring majestically across the store.
6. 53 seconds into the third attempt you finally have your key.
7. Discover you forgot your wallet.
Still a bigger security risk than having digital lock doors.