I think its just a matter of man power, they don't seem to be able to dedicate the time/talent up front to do a thorough job.
That's pretty much it. Congress sees the USPTO as a revenue source, so they aren't even allowed to keep all the money they collect in fees (and they aren't allowed to raise their fees either). And they aren't allowed to develop a backlog (they started falling behind in the 1980s, but Congress slapped passed new laws preventing that). And if they reject an application the application can be amended and resubmitted, and almost always is until it's accepted.
So basically the USPTO doesn't have the authority by itself to solve the issue, and we need a solution from Congress.
That's pretty much it. Congress sees the USPTO as a revenue source, so they aren't even allowed to keep all the money they collect in fees (and they aren't allowed to raise their fees either). And they aren't allowed to develop a backlog (they started falling behind in the 1980s, but Congress slapped passed new laws preventing that). And if they reject an application the application can be amended and resubmitted, and almost always is until it's accepted.
So basically the USPTO doesn't have the authority by itself to solve the issue, and we need a solution from Congress.