I think it's becuase the aeroplane was designed for the military at a time when the RAF had hundreds of technicians, so lengthy maintenance proceedures were not a problem for that customer. Jobs on Chippys take longer than similar jobs on Cessnas or suchlike - things are harder to get at. Ease of maintenance was not high on the designers priorities.
Also, spares can be horrendously expensive because of scarcity. As an example, some years ago we had to replace a fuel tank. This is just a rubber bladder, but it cost us £4,000 for one! In more enlightened countries, metal fuel tanks can be used to replace the inferior rubber ones at much lower cost, but as these are not 'original equipment' on the type, the CAA will not allow their fitting!