Science is a competitive game. You make your name on your ability to produce novel, creative, original work. There are number of ways you can do that. One way is to focus on a little-studied target. There are broad swaths of the biomedical sphere where we know so little mostly because people haven't looked very hard. So, if you decide to work on such a target, your competition is low and you can carve out a niche for yourself.
This is how a lot of biomedical science is done, in my opinion. Your claim to fame is what you study.
Then there are those who study in competitive fields, like cancer research, and try to study the same questions that others have but from different perspectives. This strategy works too, but given how many smart people there are looking at the same thing as you, it's quite difficult to do something so radically different from anyone else.
One more strategy is to create a new technology or tool that allows you to look at both well- or understudied topics in ways that your peers cannot. Your technology gives you an advantage and makes the barrier for competition particularly high. To create a useful and novel tool is no small task, but if you can do it, the rewards, I think, are great. For my scientific career, this last strategy is the one I prefer. I want to do my doctoral work in chemistry so that I can acquire a large toolbox with which I can then probe the same biological questions as everyone else (or different ones) but in novel, unmatched ways.
I was just reading an article in the current issue of Cell that confirmed my previous thoughts about the way most biomedical science is done (and what I don't want to do). This article, entitled, " Regulation of Mitochondrial Protein Import by Cytosolic Kinases" was literally just page after page after page of western blots. I honestly don't know how anyone would be able to keep track of so many blots. No doubt the poor grad student or postdoc who had to run all those blots worked very very hard to produce data of sufficient quantity and quality to make it into Cell. I don't want to trivialize the difficulty, skill and intelligence it takes to make a good story out of well-planned and run western blots. But the thing that always gets me when I see articles like that is question: what makes you different from anyone else if you're using the very same tools as they are? In this article, and like so many, you put your faith in the idea that object or pathway that you're studying is sufficient in its own right to garner interest - just because we don't know that much. And if more than a little is known about your focus - as is the case in this article about mitochondrial translocases - you need to do a beastly amount of work in order to set yourself apart from the pack.
I just don't find that strategy very interesting. It works no doubt, and important contributions can be made (and have been) that way, but it's just not that exciting to me. I'd much rather spend my time trying to discover new tools - small molecules in my case - and then using those tools to study things in ways that other people can't. That's a tall order, to be sure, but it's a heck of a lot more appealing than being a blot monkey all day.