A quotation from C.A.R. Hoare, a British Computer Scientist who started his career in the 1950s:

Pure academic research and applied industrial research are complementary, and should be pursued concurrently and in collaboration. The goal of industrial research is (and should always be) to pluck the ‘low-hanging fruit’; that is, to solve the easiest parts of the most prevalent problems, in the particular circumstances of here and now. But the goal of the pure research scientist is exactly the opposite: it is to construct the most general theories, covering the widest possible range of phenomena, and to seek certainty of knowledge that will endure for future generations. It is to avoid the compromises so essential to engineering, and to seek ideals like accuracy of measurement, purity of materials, and correctness of programs, far beyond the current perceived needs of industry or popularity in the market-place. For this reason, it is only scientific research that can prepare mankind for the unknown unknowns of the forever uncertain future.

When an academic leaves school and enters industry, he may be shocked at the difference between academic research and industrial work. A Cisco engineer once told me that his group at Cisco started avoiding people with PhDs, because they weren’t satisfied to improve and enhance the existing IOS code-base. They wanted to scrap it all and start over again. Cisco valued stability and gradual enhancement rather than purity and ideals.