While some will argue that we would be better off without them, if it will help preserve them within our ecosystem, I say yes. There are many animals that have gone extinct and while I don't know the current situation with vampire bats, if this will help keep them around, then I'm all for it.
I believe that even though we should not exhaust our resources on blood needs for vampire bats, it is still certainly important enough to focus some of the efforts on it. After all, we cannot just sit idly by while vampire bats become extinct. The more we know about the topic, the better off we will all be. That's humans and vampire bats.
By focusing efforts, does that mean that tax money is being spent looking for the needs of blood for vampire bats? It is known that vampire bats survive on blood and if there is a shortage of their needs for blood, do they die off, or do they go after more sources and enter more populated areas? If that is the case, then I would say there needs to be more investigative search and resources used to carefully find out the needs, and if the population needs to be aware of the influx of vampire bats. If there is no need for alarm and it is just for random research I don't feel they need to be warranted in using time/money to research.
Why would we do that? Who benefits from this study? More to the point, where would they get enough blood to feed the bats and keep the study going? I think this is a waste of time and money. Obviously, the bats are managing nicely on their own. What can possibly be gained from this?