Along with Firefly Bob, I must also have lived sheltered life!! During thirty years in towers, I rarely experienced any problems with overhead joins.
Indeed for visiting pilots, OHJs enabled the pilot to orientate him/herself with the runway and circuit direction in use, other traffic etc. They also enabled me to eyeball the aircraft and ascertain that correct procedures were being applied.
However, on countless occasions pilots making straight in approaches regularly co**ed up the circuit by giving wildly incorrect distances from touchdown........often I suspected with the intention of jumping the queue.
Straight in approaches are obviously ideal for the airline traffic, twins etc but overhead joins are ideal for learners, single engine aircraft and visitors to the field.
Just an ATC perspective!