There's no compelling reason to conclude that any of the bubbles have been caused by fraud. I certainly agree that it's possible, perhaps probable, but Gox/Willy and Tether are mostly compelling narratives; when you dig down into the specifics, it's hard to connect them to price action.

These stories fit peoples' expectations for fraud in Bitcoin, they lust for scams and intrigue.

The null hypotheses is boring but also quite plausible: bitcoin sees bubbles because price has been steadily rising and this eventually triggers positive-feedback cycles that cause the boom and bust. The insensitivity of Bitcoin price to news/events supports this hypothesis: price is the news.

The fraud narratives are more tea-leaf reading than actual analysis. Just dive into the Willy bot oeuvre if you'd like a sense of that.

Do you think a market that is easily manipulated would ever not be?

Yes, the underlying idea has always been sound enough to attract large investment without manipulation. Even if the legal and ethical true price is under $1000, that's still more natural growth than, say, an additional 20x added on by manipulation.