I think for most Biodrones (and reviewers) that is really the worst aspect of Andromeda, it's an entire new galaxy and we still have bipedal, humanoid looking aliens.
The only immediate problem with it is that it doesn't fit your expectations. There are as many theories supporting the claim that technologically advanced intelligent aliens would be bipedal and upright as there are to the contrary. And the evidence is overwhelmingly in favour of bipedal intelligent primates: we know it happened at least once.
In all scientifically plausible theories, the way intelligent life looks depends on the conditions it evolved in. You could argue, for example, that intelligent life that evolved on a planet with much higher gravity and much thicker atmosphere in comparison to Earth, would indeed look nothing like humans. Those creatures would probably be horizontal in posture and would possibly move on more than two legs (or have a strong tail).
If, however, life evolved on a planet, that more or less resembles our globe, it is quite likely they wouldn't be that much different. They would probably need to move, so we can assume symmetry (most likely bilateral, if they evolved on land). They would need to have sensory organs on the front of their body, because that's the side that meets the environment first, when they move. This means, they would probably undergo cephalization and develop a head. Since they evolved in a thin atmosphere, they'd probably be vertical creatures and with that posture two legs are much more efficient than four or more. They would also need a way to manipulate the environment - upper extremities. Most probably 2, because that's quite enough to do most tasks. One could argue, that a creature could do more tasks simultaneously, if it had more sets of hands, but that would require more sets of "eyes" or the ability to concentrate on many objects at the same time. This, however, would mean a bigger brain -> bigger head -> higher mass -> more energy requirements and so on. As a result, 4 arms could turn out to be less efficient.
So there you have it - a bipedal, upright alien with two legs and two hands is not a huge stretch, although I'm pretty sure there are many home-grown scientists on the Codex, that have their own ideas on the subject.