Originally Posted by
Loren Pechtel
This is the main reason.
There's also the issue of dirty baggage handlers. A locked suitcase takes more time to get into, they'll be more likely to go for the unlocked one.
Locks are completely useless against thieves that make off with bags.
I rather liked my key ring solution, but it took me forever to get the damned bag open with that thing securing it. I could at least open the lost lock with a toothpick in a jiffy.