This is not true. I cut wood in my home shop to thousandths with band saws, table saws, routers, good fences and good cheap measuring tools. Course I did a long stint in a master pattern shop working for a journeyman master pattern maker. With a good blade in a band saw and 3M77 adhesive and a large format printer ($300 off of ebay) as well as some magnification and a good set of sanders you can get a profile to split a .005 wide line. I have done this over and over in all kinds of applications. Thin plywood over ribs can be a very accurate airfoil. It may not be as rigid as foam backed carbon or equiv but it is pretty good as long as it is supported on a short enough interval. Wood is still the original composite material. It isn't as versatile as modern composite techniques for a one off but it is very easy to use and build light strong structures with wood if you limit 3d curvature. My material of choice for cheap QC templates is free formica scraps from a local cabinet shop. Works great and it is rigid and dimensionally more stable than aluminum and they have barrels of the stuff. I haven't done it yet but a good dremel gantry router made out of scrap printer carriages are getting cheaper and easier to get (open source) every year. One 2D router can hit a few thousandths pretty reliably. I haven't seen anyone just put a dremel in a DesignJet printer head but we are getting closer to that every year.