Why not distribute source code with ZIPfiles?

I’m _really sorry_ if this is covered in the FAQ, but I didn’t see it covered there (my wife says I have male pattern blindness, otherwise known as refrigerator blindness). I used subversion to check out the source code, but I was wondering why stable source code is not released in a ZIPfile. Yes, I know it would be a pain to submit changes, but although I’m a programmer, I don’t usually delve deep enough into the code to be making changes; sometimes it’s nice just to browse the code to see what’s what. Fortunately for me, the system I am using (CYGWIN on a WinXP box) includes subversion, but had it not included it, I would then have had to download and compile subversion to be able to access WordPress. It’s a hindrance to have to install packages (sometimes multiple packages) just to browse the code. A ZIPfile would fill that bill nicely.