Should the purpose of dating be to end up together? Is a relationship any less meaningful if you're both just looking to enjoy the pleasure of each other's company, but have no plans for the future? Is dating just a means to an end?
I would say dating is a means to an end. That end being whether you are both compataible to end up together (not that stops people breaking up & having "messy" divorces after the wedding).
As for your second question, I would say not. An example would be my now 13 year relationship with my best friends (that took me a while to count

).
We don't have plan on what the future of the realtionship is. We could end it in a year, tomorrow, today or this second. The point is I see no issue with having a relationship to just enjoy the pleasure of each other's company. Its called
Friendship. Even then dating requires one to enjoy each other's company as well.
As for the purpose of dating. I guess it depends on the individual. Some go looking for a partner, others just for the "sexual" activities obtained from it, others look for "love" and many other things. I personally see dating as a way to explore whether me and the other person are compataible to end up together. That doesn't mean I go straight out asking people I'm dating to marry me and have 5 kids with me.
<= There is a story behind that sentence. I guess to sum up my ramblings on this, who the fuck cares?
Dating is dating. As long as your both on the same page on what you want out of the relationship then good on you.
It means different things to everyone and it shouldn't bother you if yours doesn't match to others.