From Wikipedia: The English adjective human is a Middle English loan from Old French humain, ultimately from Latin hÅ«mÄnus, the adjective of homÅ "man". Use as a noun (with a plural humans) dates to the 16th century.[7] The native English term man is now often reserved for male adults, but can still be used for "mankind" in general in Modern English.[8] The word is from Proto-Germanic *mannaz, from a Proto-Indo-European (PIE) root *man-, cognate to Sanskrit manu-.
The generic name Homo is a learned 18th century derivation from Latin homÅ "man", ultimately "earthly being" (Old Latin hemÅ, cognate to Old English guma "man", from PIE *dʰǵʰemon-, meaning 'earth' or 'ground'.
I'm not sure as to the answer of why we are called humans, but I do wonder if changing the name would make a difference? Would we feel the same about ourselves if we were called something different? Is it like Shakespeare (Juliet) says in Romeo and Juliet "A rose by any other name would smell as sweet"? or is there actually something to the name itself?
You can blame the Judeo-Christian faith for that one. In the old english the term man meant 'erson', and woman meaning 'from man', a reference to the Biblical fable of God making woman from one of Adam's ribs.