Sub Articulo 73.2
Standard typography says that a normal single column of text should be
between 1.5 and 2.5 alphabets wide (one rule of thumb). This works out
to be about 45-65 characters of normal text. Anything outside this
range is likely to get hard to read - it has to do with the ease of
following a line and finding the start of a new one. Longer lines make
life easier in that it's a slight effort to find the start of a new
line, but longer lines make it harder in that it's tricky to follow a
*very* long line, and hard to find the start of the next line if the
lines are long.
Now then... Way back when when typewriters ruled the Earth and people
still lived in caves, people used 1 inch margins on A4[1], foolscap
folio, and US letter paper. This is easy to remember, and gives a
suitable column width with a normal typewriter - about 65 characters if
I recall correctly (10 characters per inch is typical from a
typewriter). If you apply the same rule of thumb to (say) a 10pt
proportional fount like cmr10, you get far, far, far too many characters
across a single column.
A better solution to the `huge margin' problem is to use a multiple
column layout, or a larger base point size and possibly a wider fount.
The reason the standard LaTeX layout looks strange is that US letter
paper and A4 paper are both too wide for single column printing - it's
the fault of the paper rather than the layout. The layout choses the
widest column width you can expect to get away with, but it's still too
narrow for the paper.