I've always thought that people underestimate the mental acuity needed to find simple truths within complex systems and to use them to achieve useful results. Especially in academia, many professors, who are wedded to particular models, go so far as to dismiss simplicity without sufficient consideration. It was not always this way. Among the older philosophers, you can observe a strong affinity for simplicity. Figure…
I am not sure why people think of complexity as something bad or undesirable. Everything I can think is extremely complex and probably cannot be explained in simple terms without missing much of the context and beauty behind it. In my opinion, its not simplicity, its actually the complexity that adds beauty and meaning to everything.
When it comes to getting things to work, to make things happen, to understanding things... our major bottleneck is the "size of human skull", your cognitive limits.
Descartes gives the example of visualizing a chain made up of many links... at any point, you can only look at say, maximum 4-5 links, you can never see all the links at the same time. That is, in fact, it is impossible for a human to "see a whole chain"! You are "making it up", even with such a simple operation as "see". Therefore, due to such horrendous limits to cognition, you are forced to implement some sort of simplification mechanism.
So the context of discussion is (2) not (1). The people interested in making things happen in the world, to obtain correct/useful/functional/practical viewpoints, tend to gravitate towards simplicity by necessity. There is no other option.