Ahh... This is the real issue, isn't it?
I believe there are ways we could quantify shaft playing characteristics: density, balance, stiffness/deflection, radial consistancy, vibration, etc.
It would require standard measuring equipment and a standard set of things we decide to measure. (This is difficult to do. It will take more than one large manufacturer to adopt the same standards, and that's not likely.) We are beginning to see more numerical quantification on tip hardness.
Standard measures would remove a lot of marketing hype while still allowing for personal taste. The "feel" I like in a shaft will not be the "feel" someone else would like. With standards, I would be able to specify my preferences within ranges, like ordering a diamond.
Standard measures would also accelerate the use of more engineered materials, like laminated or even synthetic shafts ("God forbid" some of you are screaming).
For now, you are stuck with "feel."