Maple is not really that uncommon on acoustics. I would guess it has
to be the second most popular choice behind mahogany. All the soft
maple necks on old parlors and so many Chicago instruments, all of
Gibson's maple necks in various eras and models. There are still a good
many builders using laminated maple necks today.
It does strike me as ironic though, that I have no problem finding 12/4
mahogany at my lumber mill, but have a hell of a time finding any maple
thicker than 6/4. Could very well be another example of supply
influencing usage in our trade, and that historical usage in turn shaping
our modern predispositions and preferences. Like flatsawn maple necks
on Fenders - it's only what people want now because that's what they're
used to and have learned to call good. Then that's only because 4/4 flat
sawn maple was what Leo could find suitable, cheap, widely available, and
easy to finish.
And like Ken said, it's easy to work with. It's usually quite a consistent
wood with a relatively low chance of finding flaws and knots and pits as
you are shaping. It's stiff enough to do the job, and look good too. I'm
not saying there's no tonal reasons for mahogany over others, but I doubt
that's the main reason it became popular. While we have a habit of
looking for more inspiring reasons as to how standards like this develop
in our trade, there are usually much more simple business decisions
behind it.
Cherry is fast becoming a popular alternative as well. Easier to work than
maple, a mellow color more akin to mahogany, yet requires no pore
filling. Seems like an obvious choice for me. I'm not a big fan of walnut
though, which is probably just because I associate it so much with
dulcimers.
Clinton