If you really want to know more about why English has such inconsistent spelling, you should read:
The Mother Tongue: English and How it Got That Way by Bill Bryson. Though it sounds dry reading, it's actually quite fun to read.
The short version is that "English is the result of Norman soldiers attempting to pick up Anglo-Saxon barmaids, and is no more legitimate than any of the other results."
— H. Beam Piper