Are most carbon frames not made in china?
Vast majority are made in the far east, that's correct.
Carbon however is not largely dependent upon a clean working environment. I myself produce carbon parts using vacumn bag techniques as do many enthusiasts of this material.
With titanium manufacture a extreme level of purity clearness is needed because any imperfections at all introduces weaknesses to the manufacture process and the product which may not be visible to the eye.
Even things such as using the wrong type of welding process will result in a frame which looks OK but will feature brittle joins due to excessive oxygen and nitrogen being absorbed.
IMHO carbon manufacture requires knowledge, Titanium requires skilled craftsmen as well as knowledge, its not an easy material to work with.
If something is massively cheaper, you have to ask how the savings are being made, is it material quality, manufacturing environment, skilled workforce? - ultimately someone is still making money from it.