Charlie: As you may know, the standard locks used in the US, pin tumbler locks, are very easy to pick. Just Google “lock bumping” and watch the videos showing how easy it is.
When you stay in a different hotel every night you deal with a lot of locks. In Navarra, where we started, I noticed that almost all the locks were the more modern kind with drilled holes on each side of the key, still pickable, like all locks, but only by actual experts, not by someone who watches an Internet video. I was impressed.
Getting onto the Meseta things have changed. All the locks are the standard US kind. I guess this is a poorer area. The Northeast part of Spain is more industrialized and richer.