I see this model of science as potentially misleading. One obvious reaction to the "too many bricks" idea is to try to put together some grand theory yourself (an "edifice"), but this nearly always means becoming a crank. Likewise, I don't think see how a scientist has ever been stopped by the mere existence of too much trivial research, though they might be diverted from better work by the need to produce mediocre work quickly. I prefer Hamming's questions: "What are the most important problems in your field?" followed by "Why aren't you working on them?"