Of course a ratio describes an angle just as accurately as any other method. What peeves me a bit is that people use these same ratios, but measure differently or to different places on the razor, and act as though that doesn't effect the angle. One person using the 1/4 ratio always measured the full height of the razor regardless of how far up the actual grind line was relative to the top of the spine.

Also people argue that anything between 15-20 degrees will shave fine. That is true, but I feel a considerable difference in how those two angles shave and I much prefer the feel of an edge with a bevel angle closer to 15 degrees. This may be subjective on my part because when I make or hone a razor I always know the bevel angle before the test shave.YMMV