Or that the computer always works. Or that the software never has problems. Or that they always have the memory and peripherals they want or need. Begin with the end in mind. It means to know where you're going so that you better understand where you are now and so that the steps you take are always in the right direction.
All teachers plan.
It is keeping the kids busy. It is a reward for doing good work or finishing an assignment or earning a grade. Mainly they are using it because it is there. Effective technology-using teachers choose hardware, software and technology with desired student outcomes in mind. It becomes an integral part of the instruction, not an add-on.