Part of it has to do with the differences between Latibn and Greek. The former is curt, so the Roman Liturgy early on became shorter than the Greek Liturgy it replaced.
In these rites I discover that something is approaching me here that I did not produce myself, that I am entering into something greater than myself, which ultimately derives from divine revelation. That is why the Christian East calls the liturgy the "Divine Liturgy", expressing thereby the liturgy's independence from human control.And, the liturgy is an expression of the church community toward God and toward one another, as well as a teaching tool for novice churchmembers and a vehicle to lift oneself up to God. I cannot imagine the uproar which would be heard if a change in the liturgy were suggested to us.