Most scientific projects are assigned not because it they reasonable to do, but because supervisors wants their students to be busy. Otherwise, they could start to dive deep into some topic and get terribly confused. Most professors think that their students must spent all their time calculating and hence propose easy projects where it is clear what the result is and that the student will manage to do it. There is no deep idea behind most current research projects, but instead people take what exists, and just add a little bit (an $\epsilon$). The main motivation for doing this is, well, it's not forbidden, so… why not? Of course there are infinitely many ways to add randomly something to all the existing ideas and thus the probability that any of these ideas is correct is almost zero.
Most scientists pick up on ideas which are dominant, which come from living figures, and develop them incrementallyLee Smolin
Most published science is mundane. It is the easiest to get published and the easiest to get funded at a modest, sustainable level—though no funding is easy to get these days. It is also more likely to be right, precisely because it is incremental. Just as rock-solid financial investments are an important part of any balanced portfolio, so the mundane science is an important part of the science portfolio. But I suspect many scientists, even some who are recognized as leaders in their field, are unwilling to acknowledge their lack of adventurousness.
In defense of Crazy Ideas by David Stevenson
An often-used strategy is adding a single elementary particle for the dark matter and, possibly, another particle to mediate a force between the dark and visible sectors. This approach is justified by criteria of “minimality” or “simplicity”. While I agree that, given our ignorance about the dark sector, this is the first thing to try, I also think that the approach, rather than “minimal”, looks awfully shortsighted. We have ample evidence that nature follows a grand scheme. We recognise in the Standard Model features of this grand scheme. Adding one or two particles only for the reason of generating dark matter is not something that nature would do, if she indeed has a grand scheme in mind.The Dawn of the Post-Naturalness Era by Gian Francesco Giudice
No one starts studying physics thinking „oh yeah, one day I want to calculate cross-sections for a living“. However, that's exactly what a lot of people do nowadays and did for the last 30 years or so.
“The disadvantage to the trajectory of going with what works and then changing a little and changing a little is that you might just be in the basin of attraction of the wrong idea from the start and then you’ll just stay there for ever.” Nima Arkani-Hamed
“In this talk, I will give arguments for the position that it can be useful to refine a theoretical framework to the point at which it is a mathematically precise and consistent scheme, even if, as is sometimes the case, the resulting conceptual frame has physical deficiencies. I will offer several examples to illustrate the point. Of course,it is only occasionally that this sort of enterprise can help in the hunt for the Green Lion, the ultimate Lagrangian of the world. A. Wightman in “The usefulness of a general theory of quantized fields
Is the purpose of theoretical physics to be no more than a cataloging of all the things that can happen when particles interact with each other and separate? Or is it to be an understanding at a deeper level in which there are things that are not directly observable (as the underlying quantized fields are) but in terms of which we shall have a more fundamental understanding? J. Schwinger