Something I've been trying to express concisely recently is the concept that using (or making) something that is too complicated/complex for the user to understand/fix can be a bad thing. Is there a short phrase or analogy that expresses this concept?
An engineer may choose to make a device that is "fool proof", something that can't be adjusted incorrectly, won't succumb to environmental conditions, recovers from several failure conditions, etc. The problem is that eventually that device becomes be a sealed container, using custom parts, with no possibility of disassembly and repair by the user. This could easily apply to software as well.
The goal may be reduced materials, lines of code, reliability, elegance, etc. The problem is that the complexity becomes a barrier to entry for the user to understand it, and the user becomes dependent upon the creator. Nothing lasts forever, but if failure is sufficiently delayed the user(s) may outlive the creator. I've seen this concept in science fiction (e.g. the Foundation series by Isaac Asimov, nuclear reactors still exist, but no one knows how to repair them).