From my own observations there two general reasons: * Assembly is seen as [near] zero value add step, therefore self assembling is seen as an easy opportunit

From my own observations there two general reasons: * Assembly is seen as [near] zero value add step, therefore self assembling is seen as an easy opportunity for savings, especially when assembly is actually sold service. * People think that assembly is generally done by minimum wage employees coasting through the day and half assing tasks, therefore self assembly with a little bit of focus and dedication is seen to lead to higher than default assembly quality.