[nsenifty]

> what you speak is what you write and what you write is what you speak

I am not a Sanskrit scholar by any means, but IMO, being phonetic is not necessarily the reason for that. It is more so because Sanskrit words are often derived from a small set of root words. In other words, the words are actually descriptions of things using smaller components. In this case, the root is Bha which means "to be" or "to exist", from which there are words derived such as Bhavatu - "so be it", Bhavita - "existed", Bhavana - "place of existence/dwelling".