Gordon Moore predicted the dramatic increase in transistors per chip in 1965, and his prediction has held for decades. Some industry analysts insist that Moore’s Law has been a predictor of chip design, but others say it is a motivator for designers of new chips. In your opinion, who is correct?

An argument can be made for both sides of this question—and your answer should come down to which argument you most agree with.
Moore's law, as it is now referred to, was first predicted in an internal paper for Electronics journal in 1965 by engineer Gordon Moore. Under this "law," Moore predicted that the number of transistors per silicon chip will double every year. The law was adjusted to predict chips doubling every two years in 1975, reflecting slower development trends and the need for increasingly sophisticated technology. Given its accuracy, researchers and developers have used Moore's law to predict industry changes and set technological targets.
Obviously, there is a physical limit to this law—and if it were to continue its predictions, by 2025 transistors would be nearly the size of an atom. Since 1965, technological advances have supported Moore's law—transistor size has continued to decrease with the development of a host of engineering breakthroughs, including CMOS, silicon straining, VLSI, immersion lithography, high-k dielectrics, and transistor process technology (these transistors are now tens of nanometers in size). However, should development continue at this pace, it will be less than a decade until engineers may need to move into quantum chip computing (a breakthrough that seems unlikely given the laws of physics).
One could argue that Moore's law is a "self-fulfilling prophecy"—that no matter whether Moore simply predicted the pace at which technology would develop or whether chip designers purposefully strove to meet his predicted rate of development, the trend and timing is the same. It is up to you to weigh the evidence and decide if you agree that Moore's law is observational in nature or if it provides a timeline and motivation for engineers to set development targets.