I think we may be too harsh or hasty in rejecting the notion of intelligent design outright. So I'm going to suggest that we take the ID hypothesis and consider what inferences we might make about the nature of the designer or designers, based on observations of biology and the natural world.
First, the strongest inference that can be made is that there is probably more than one designer. I make this suggestion as an alternative to the other possible conclusion: that there is a single designer who is both stupid and neurotic.
Consider, there are numerous examples of superior designs throughout nature that are nevertheless overlooked in the design of other flora and fauna. One famous example is the eye of the octopus, which is notably superior to the mammalian eye. Why is the superior design not used? Clearly, the mammal designer did not have access to the better design. For a single individual that would be enormously stupid, but for multiple designers it could easily happen. Indeed, we do not even have to hypothesize that the mammalian designer did not know about the octopus, merely that the patent (or something analogous) has not run out. Similarly, we can say that the reason why there are no centaurs is that the mammal designers do not have access to the six-limbed design, while the insect designers can’t design decent endoskeletons.
So far so good. But the neurotic design aspects are a little harder to understand. Simply put, the designer(s) have a great deal of difficulty eliminating unwanted features from their designs. For example, if I go out and cut into a current model Cadillac, I will not find vestigial tail fins, despite the fact that all such creatures had them only forty of so generations back. In fact, all traces of tail fins disappeared in a single design cycle. But human still have vestigial tails, as well as many other such archaic features, to say nothing of the ontogenetic features of fetuses. In fact, vestigial features are typical in practically all organisms.
Why is this? That is hard to say. One resists the conclusion that the designer(s) are so neurotic as to be unable to ever discard anything. Indeed, discards do occur—by the complete elimination of a species, genus, etc. that contains that trait. That is rather like throwing the baby out with the bathwater, however, and it seems to result in a permanent loss of those design ideas. Perhaps intelligent designer intellectual property law works similar to our own trademark law, where failure to protect (use) a trait means that the trait is no longer available for future designs. In any case, this is another situation where multiple designers makes more sense, primarily because game theory tells us that such seemingly irrational behavior can often result from rational behavior of individuals in groups.
In summary, therefore, it may very well be that the camel was indeed a horse designed by committee. The ethical, moral, and religious implications of these insights is left as an exercise for the reader.