Within biology, intelligent design holds that a designing intelligence is indispensable for explaining the specified complexity of living systems. Nevertheless, taken strictly as a scientific theory, intelligent design refuses to speculate about the nature of this designing intelligence. Whereas optimal design demands a perfectionistic, anal-retentive designer who has to get everything just right, intelligent design fits our ordinary experience of design, which is always conditioned by the needs of a situation and therefore always falls short of some idealized global optimum. No real designer attempts optimality in the sense of attaining perfect design. Indeed, there is no such thing as perfect design.
Constrained optimization is the art of compromise between conflicting objectives.
This is what design is all about. To find fault with biological design because it misses an idealized optimum, as Stephen Jay Gould regularly does, is therefore gratuitous. Nonetheless, the claim that biological design is suboptimal has been tremendously successful at shutting down discussion about design. Interestingly, that success comes not from analyzing a given biological structure and showing how a constrained optimization for constructing that structure might have been improved. This would constitute a legitimate scientific inquiry so long as the proposed improvements can be concretely implemented and do not degenerate into wish-fulfillment where one imagines some improvement, but has no idea how it can be effected or whether it might lead to deficits elsewhere.