Alsthuller once said: "The system tends to uniformity". We were talking about a social system and Altshuller was explaining why those who are not like others get thrown out. But his assertion was generic.
However technical systems exibit much weaker tendency to uniformity than those consisting of humans. The latter indeed tend to uniformity very strongly. A lot of phenomena in human history can be explained by this tendency: religious/ideological strife and quests to convert other people into their faith, intolerance to other way of life, policies of melting pot and attempts to create a racially integrated society, etc. etc.
By the way, the way of life has many aspects and one of them is how people work and produce goods. From here follows intolerance to others' way of work, to organizing working processes, and to the way of production. An ultimate example of this type of intolerance can be found in the events preceeding the American Civil War. Industrial way of life (and production) in the North could not stand the manual labor based way of life (and production) in the South. North wanted to mechanize and industrialize agriculture in the South. South, conversely, wanted to bring slavery and the way of production associated with it to the North. This was as a conflict between people of stone and bronze ages. Wealthy industrialists could not stand wealthy slave holders (and vice versa). But on the surface it appeared that the abolitionists were fanning out the conflict.
For technical systems the tendency to uniformity is much weaker, however. Components do not become identical unless they perform identical functions. But the type of material of which they are made is mostly identical. Nowadays it is metal (for machines). There were times when machines were built mainly of stones, then mainly of wood, now mainly of metals but soon will be built mainly of composite materials. Thus, for technical systems tendency to uniformity mainly exibits itself in uniformity of the type of material of which technical systems are built.
Why do systems tend to uniformity ? Is it inherent in humans to be intolerant ? Are systems consisting of uniform elements better that those of diverse elements ? In some respects and under some circumstances they are but in others respects and under other circumstances they are not.
As paradoxically as it may sound but diversity is constantly being born out of the tendency to uniformity.