You do realize the FAA is made up of several divisions, right? ATC, Aircraft Certification, Aircraft Records, Airman Records, CAMI, the people who maintain the electronics and Nav Aids, Airports Division and several more. Flight Standards is the part that oversees airman certification, and is fairly small (5000 or so employees) Out of that 5,000, less than half are Inspectors, and not all of those inspectors are pilots (airworthiness, avionics, cabin safety, dispatch) Scatter the remaining Operations Inspectors (pilots) around the country, and they have certificate oversight (Part 135, 121,125, 133, 137, etc) plus hotline complaints, on demand pilot certificate jobs (name change, renewals, SOE removals, etc, etc) accident duty, investigations of pilot deviations and a whole host of other smaller task, and giving Part 61 pilot certification becomes very minute, if at even possible.
Congress approves and passes the budget. Hiring more Inspectors hasn't been a priority for them.