What you say might be true - although there are many people who doubt it, with some quoting research papers - but it simply doesn't answer the question asked, and is pretty much a complete non sequitur.
People use what they use. So if they use base twelve or base sixty or binary or octal or hexadecimal or base five because they have a simple way of counting in that grouping then that's what you'll see them using. Just because we don't use it today doesn't mean anything.
Using thumb, press on each off the three segments of the finger starting at end. ---X---X---palm. Four fingers gives twelve positions, At each twelve, fold one finger and /or thumb to palm of other hand, easy.
Have a read of Knuth for other counting systems, including binary (English Wine Merchants)