My guess is that it'd be difficult to figure out what's a tracking URL and what's just a normal parameter. Or maybe because HN is supposed to be minimalist: yo

My guess is that it'd be difficult to figure out what's a tracking URL and what's just a normal parameter. Or maybe because HN is supposed to be minimalist: you upload something and know that people will see what you uploaded, unmarred by HN's modifications. I'm looking at you, Twitter.