I have a similar experience with XeLaTeX. The "it's not unicode unless you jump through hoops" and "oh you want to use opentype fonts? I'm sorry to hear that" of plain LaTeX2e always make me go back to XeLaTeX instead.
You're still using (mostly the same) plain old LaTeX 2e with pdftex, xetex, and luatex (pdflatex, xelatex, and lualatex). Those are just 3 different engines for Knuth's original tex. As far as I know, some parts of all 3 are written in WEB (which is a language that persists mostly because Knuth's TeX is written in it).