Poort quality

I returned a Xiaomi MiBox S Ultra HD 4K Media Box at Incredible connection yesterday on behalf of my Father. The technician Booked it in for repair. The technican made it very clear that the quality of this product is not as good as it should be. The unit I handed it was in an excellent condition. What is going on ??? Are we now paying for poor quality electronic goods and need to be satisfied with it???? Kindly explain