On a conceptual level, USPTO is operating on the same procedures that was initial created more than 200 years ago. Practically every other form of government administrative operations has change, but the patent process has not.

Following 19th century government standard, USPTO is only really responsible to take in a patent request and check its own records to see if a patented idea is new or not, and then allow the skill government clerk who took the request to make a judgment based binary decision. The assumption in 19th century government process is that anything not in the records are not something for which the government can be held responsible to make a judgment on. Anything beyond this is assumed to be the courts and juries responsibility.

And in the past they did also have a few safeguards. A working model had to be added in order to make sure that function and copy of the idea is guarantied. The scope of patentable ideas was also narrowed down to a few areas for which a skilled government employee with a massive record could make a relative good guess if something was novel or not. Both was removed about 50 years ago, and a explosion of "new" patents has been requested ever since.