Want to second this comment. Spatial efficiency, insert and locking mechanisms, electrical characteristics, mechanical strength characteristics, machine pickability/placeability, solderability, thermal characteristics, thermal impact to overall system, environmental seal properties including water/saline air/weak acids/weak bases, orientation guarantees, safety factors such as susceptibility of shorting with different categories of pollutant including metal dust, longevity/susceptibility of contacts to build-up of dust, formal fire engineering properties (including combustion temperature/off-gassing), fabrication cost including line purchase/scheduling/maintenance and hard tooling fabrication/longevity/maintenance, color coding for human error reduction in assembling and maintenance, documentation and translation, distribution and recalls, etc. That's just the connector. Now look at regulatory outlook, availability and all of the above mentioned concerns for the relevant cables and their fabrication processes...