Cardboard adolescent, thanks for a well-written reply. Anteater, you also make a solid, well-written point although it has been made earlier in this thread by several, including myself. Most seem to agree on that one.
I don't think Schopenhauer is right. Biological theory and understanding is explaining a lot of what philosophy has been trying to explain earlier. One of my friends who I first met during my biology bachelor already had a masters in philosophy, but started over again with biology for this very reason.
We are here because our lines have persisted. At some point, life was probably little more than advanced molecules able to replicate themselves. There would be many different versions of these and they would compete for shared resources. The ones that were most efficient, probably at replicating themselves, getting resources, possibly destroying their competitors etc. persisted while the others died away. This is a kind of driving force that is still with us today. Unless you're a mutant, you have an inbuilt desire for self-perseverance and reproduction (at least sex, evolution may not have caught up with the idea of preventatives just yet). Although our genes "know" this, our brains don't always and our cognitive abilities have given us the luxury of asking what the point of it all is.
This point of view has a lot of scientific backing and with it comes a certain practicality. How to persist and replicate are problems with practical solutions, many that are instinctive for us. According to Schopenhauer, there may not be a point in taking care of your kids, but we still do it. It's programmed into our very nature and while we are certainly able to reflect on his thoughts, I don't think we can actually rise above our nature and fully rid ourselves of every natural urge like eating food, protecting our children or not jumping off tall buildings.
So what I'm saying is that practicality is more than just a viewpoint, it's built-in and it makes sense for us to follow it.