Why is TeX such a mess?

The simplest, modern route to using T_EX is to download TeX Live, but it's such a huge mess. Even the lightest installation can be hundreds of megabytes, and there are so many files it needs its own package management system.

Why can't I just download pdftex and run pdftex foo.tex and get a PDF? Why is there so much cruft for what is supposed to be ``traditional'' UNIX software?

TeX itself is actually relatively small, around 23K lines of Pascal for the basic .tex -> .dvi functionality. All the rest of the bloat is in crap that only a small subset of TeX users use or even know about, like extra fonts, packages, etc. Don't blame TeX, blame the idiots who shovel every-fucking-thing into their "TeX distro", like the same thing with Linux distros.

All you really need is TeX itself and a suitable DVI output converter. dvipdfm is relatively small and easy to use.