The majority of rasps have bitey edges, for sure, but there are at least two 'safe-edged' wood rasp/files that I know of. Paul Sellers reviews the Shinto "saw-rasp"
here.
There is a
second style, also made in Japan, which looks like a bit like a soft-metal float and can be had with a safe edge.
Planemakers' floats are toothed on one surface only.
I suppose another way to answer the question is to say that woodworkers generally don't use rasps & files in quite the same way a metalworker does. Planemaker floats are used for precision fitting, similar to the way you might fit metal parts, but rasps are most often used for tearing off (comparatively) large amounts of material using a combined cross-cum-draw-filing action and the toothed edges help 'start' the cut (or so it seems to me). I do have one of the Japanese 'float rasps' and very occasionally take advantage of its safe edges, but most often, when working a sharp rightangle edge in wood, one uses single cutting edged tools like a chisel, rebate plane, etc. A rebate plane is the woodworkers hand-driven equivalent of the milling machine...
Cheers,
