Looks like I didn't make myself clear enough. My point was, a lot of people *only* sharpen the micro-bevel on a knife and nothing else at all. Especially folks who use a sharpening jig like Lansky or Gatco. On blued or phosphate coated blades that's pretty much the only way to go unless you want to ruin the finish on the main bevel. Repeated sharpening of the micro-bevel alone is going to change blade geometry and you don't need to do a lot of math to figure that out.

P.S.: I'm afraid you have confused a couple of things about bevels and blade geometry. Check out these two links for a proper explanation:
http://www.ragweedforge.com/grind.html
http://en.wikipedia.org/wiki/Primary_grind