I don't mean to be dismissive but it sounds like you're simply not familiar with the research in the areas you're discussing.

Also, on your latter point, doing research is not as simple as 'exploring possibilities, finding a hit, then exploring similar possibilities.' The problem is that research-space is an extremely high-dimensional, bumpy space. Simply finding new avenues of research that would produce results - null or otherwise - is often a non-trivial problem that requires a lot of intelligence and wisdom. For one thing, it would be a waste if the avenue had already been considered before. And when you find some new possibility, actually evaluating that possibility is itself a non-trivial problem that frequently requires a lot of money and time to do. And then when you get the result, it's common for the result to be only slightly significant, and come with a lot of caveats and special conditions, requiring further study just to make sure it's not a fluke.

From the outside, it can seem like science consists of a bunch of 'clueless' workers and the occasional genius who makes an astounding discovery. In reality, everyone is essentially clueless in the grand scheme of things, and most 'major discoveries' are only deemed so years after the fact.