John, the way I read this is that the weather argument (ergo aircrew negligence) revolves around a degree of evidence and some subjective (albeit based upon experience) joining of the dots regarding airmanship. Conversely, the whole airworthiness issue is a very objective and necessary discussion, regardless of whether it actively contributed towards the crash.
As someone previously stated, two wrongs don't make a right, but to ignore some very convincing issues highlighted by the crash whilst pursuing a hypothesis which inevitably has some doubt due to the lack of CVR/ADR is, at very least, disingenuous.
Yours
CGB