Not all speculation is pointless. There's a point in knowing that the evidence for Turing's suicide is inconclusive.

A recent biography of Van Gogh challenges the evidence for his suicide too.

By the same token we should give up on things like archaeology as well. We will never know for certain, but we can reason that given the evidence we do have, such and such is a likely scenario.

I wasn't speculating either direction about Turing's death, but what I said regarding Copeland's statement was correct.

Judging someone's state of mind by what they project externally is not an accurate approach. Taking a single psych course would inform you of that, so would knowing someone that has committed suicide without the cliche external signals.