A typical setup includes changing the strings, adjusting neck relief, adjusting the action, the nut height, the harmonics, balancing the pickups, cleaning and time proofing the electronics with the appropriate cleaners, polishing the frets, oiling the fingerboard.
Major guitar manufacturers produce between 20 000 and 100 000 instruments per month. Now, if you multiply that figure by the average setup time of 37.5 minutes, a manufacturer would need 12,500 to 62,500 man hours per month to setup every instrument made. So, if I tell you that no manufacturer sets up their instruments before shipping, you can understand why. It's a simple and logical business decision to pass on the responsibility of initial setup to the instrument dealership and a professional luthier. And because every player has his/her own style, the instrument needs to be set up to the unique tastes and characteristic style for the player. This is true regardless of the make, or model of a guitar. You may even have invested major dollars in professional level instruments from well-known manufacturers like Gibson, Fender, Gretsch, Martin and others. These instruments simply have more potential. You can tune a Honda Civic for track day driving, and it will be great, but it still won't beat the Ferraris.
And here is where the seasoned experience of a pro luthier comes in. Knowing that everyone needs something a little different and that instruments are never setup by the manufacturer, you can understand why getting a new instrument setup is important. Furthermore, guitars are typically made of wood (typically). The natural fibres of wood will cause it to change and move over the course of an instrument's life, especially between seasons and especially in Canada's climatic conditions of warm summers and cold winters. For acoustic guitars, the seasonal changes can be felt more drastically and seasonal setups can be necessary. But this depends on the instrument. Also, guitar components such as frets, pots, tuners, nuts and saddles, wear over time.
Preventive maintenance is the best solution to caring for your instrument. Your prized instruments will last for generations and bring your many enjoyable gigging and riffing hours. You should have your instrument setup by a professional at least once a year. It's called guitar sensibility.