The Tau are awesome in that they take the best of what other races have, and incorporate it into their own. They have a vast and rapid sense of technology – able to innovate and avoid stagnation without fail. The Tau are innocent and curious – aware of the dangers around them – but not closed to exploring the unknown, because not everything is a threat.

And can these be the seeds of failures yet to come?

The Tau might be safe from the Warp, but not all the races they will encounter might be. Chaos is not ignorant. Chaos adapts and learns. Corrupt and destroy the Tau with the "allies" they find. Out number them with vassals... then strike in whatever insidious strategy will work: political, military, or otherwise.

Long ago, Mankind went too far with technology, and created AI's that turned against him. The Tau are proud of their technology, and believe themselves the masters of it, but so did Man. Pride before the fall... Then there are the C'tan – the TRUE masters of mechanical technology. It isn't beyond their capabilities to corrupt the very tools of the Tau for their own ends and turn it against them.

While it's true the Galaxy is full of wonder – it's also full of hidden dangers. The Tau might know of Chaos and can identify the taints to avoid. The Tau might know of the C'tan and can identify their handiwork to avoid. But the Galaxy is filled with horrors NO ONE knows about, or has long forgotten... in their "cautious" search for knowledge, the Tau might rediscover and awaken something, that the other races would have simply destroyed or further buried: sometimes ignorance is bliss.

Are the Tau their own worst enemy?