I'm far from an expert but I use LaTeX, and I distinctly remember there is some oddity such that you have to put an empty comment at the end of a specific line in the middle of some code that generates multi column figures, or else the layout gets messed up. That sort of thing just shouldn't be possible in anything that has the right to be called "elegant".
>"The % (between \end{subfigure} and \begin{subfigure} or minipage) is really important; not suppressing it will cause a spurious blank space to be added, the total length will surpass \textwidth and the figures will end up not side-by-side."
I think many of the ills of this type this can be traced, at least in part, to TeX's only-partial whitespace invariance.
The shifts in behavior with an added newline (or absence thereof) or a comment, as above, simply wouldn't happen if the language ignored whitespace outright.
Of course, requiring tags for newlines/paragraphs would make raw TeX as un-readable as raw HTML. It might be worth the trade for the predictability, but for the era in which TeX was written, one without IDEs or LyX, I suspect that Knuth made the right choice.
I am not going to argue about the tastes here but please consider the fact that TeX is a typesetting language. Ignoring whitespace altogether would make .tex files unreadable (as a comment below states). I am again puzzled by complaints about whitespace treatment in TeX (which has facilities for handling it, like \ignorespaces) at the same time having no objections to the choices made by, say, Python (which to me makes a totally wanton decision about such, also I am not suggesting that you personally are inconsistent in your opinions). Also, poorly written LaTeX macros in this case are not a reason to blame TeX itself.
Edit: here it is: https://tex.stackexchange.com/a/37597
>"The % (between \end{subfigure} and \begin{subfigure} or minipage) is really important; not suppressing it will cause a spurious blank space to be added, the total length will surpass \textwidth and the figures will end up not side-by-side."