There is no block size limit--it is a shared dream from which we're now waking up from.
Bitcoin is governed by the code people freely choose to run.
It's not that simple. Your oversimplification comes from one of the requirements of effective propaganda. Simple enough to be understood by the masses. What do they want? They want democracy, they want to feel they have the power. Tell them what they want to hear.
The current block size limit comes from the current consensus rules. Changing it requires creating a blockchain fork, like cloning bitcoin and hoping to kill the original.
Bitcoin is not 'governed' by anyone.