Why are plug sockets positioned on the bottom half of a wall?

Answer 1

Here's the deal: Although there are unique National Electric Code (NEC) requirements for specific types of buildings like public buildings, hospitals, schools, etc., receptacle mounting heights from the finished floor in a residential dwelling are strictly up to the owner or general contractor. They are primarily located on the lower half of the wall purely for convenience. In the case of the other types of buildings I mentioned, there are handicap and safety codes that come into play with minimum mounting height requirements.