Without Mekboyz, Orks would lack for light, power, transport, and even guns (they lack for sanitation regardless, but that's another story). Whenever an Ork needs something built, be it a shiny new Shoota or the Warboss' new ride, they go straight to the Meks. Furthermore, an Ork with teef to spare will take existing kit to the nearest Mek in the hope of having damage repaired, and maybe some kustomising done. It is a rare day that the customer gets what he asked for, but whatever the Mek turns out will normally be fairly flashy all the same.