Wait until you get married, then you'll understand ;) Wedding registries, baby registries... And in many cases that type of gift-giving extends to Christmas and birthdays.
I agree with you that it is nice to be surprised. I am just pointing out that there are legitimate uses for the "clinical" approach to gift giving: wedding and baby registries are quite common. If you don't know the newlyweds/parents nor the contents of their house very well, the registry can go a long way to giving them a gift that they actually need and will use.
Cheers
Still, the idea that somebody has set up a list of 'acceptable gifts' sticks in my craw.
I have a friend that always gives a wooden trencher board as a wedding gift for anybody. Different enough not to be duplicated.