Why on earth would a system designed for self-defense and survival be passed down with superfluous movements?
Some different views to that:
Various techniques work for different body types and/or temperaments.
There isn't always a "one size fits all" solution.
Like John mentioned, sometimes for beginners something 'else" is needed.
An example is:
Stage 1) Block and counter
Stage 2) simultaneous defense and counter
Stage 3) attack is defense / defense is attack.
Of course some systems do all that with very little in terms of techniques, look at boxing, but on a whole, variety of options is NOT a bad thing.
Psalms 144:1
Praise be my Lord my Rock,
He trains my hands for war, my fingers for battle !