Sut, You've answered yourself. You have a feeling that it's pointless, and so it is. Just get what you know and love, and PLAY the things! The rest is just used up hard drive space. If it means nothing to you then what's the point?
All this stuff that's out there is valuable IF it has meaning to YOU. If it hasn't, why bother? Just because you can, isn't a good enough reason... Spend your time playing, not downloading - a bus might run you over tomorrow, and you will have wasted your last hours collecting stuff you don't even like! (well, let's hope it DOESN'T!
Life is for playing, not downloading.