Says who?
When the Creator of the universe tells you "this is My Body" you don't contradict Him.
Besides, you've never heard of trinitarian theology? Your assertion is the same one the mohammedens use to deny the Trinity.
And the problem for the RCC is that it takes this misconception and extrapolates it into an enormous web of idolatry, such as encouraging men to fall down to the stock of a tree, and praying to wooden depictions of dead people, and making Mary a co-reemer alongside (some would even say ahead of) Jesus Christ.
It all stems from the same error. The RCC worships tangible things when we are told to worship in spirit and in truth.