alt Hacker NewsUUIDs aren't random by design, and the structure is not pointless. Calling something you don't understand "stupid" is probably not a good approach to life.
One example where UUIDs are useful is usage as primary keys in databases. The constraints provide benefits, such as global uniqueness across distributed systems.
The global uniqueness of a uuid v4 is the global uniqueness of pulling 122 bits from a source of entropy. Structure has nothing to do with it, and pulling 128 bits from the same source is strictly (if not massively) superior at that.