I'll give you a reason: it will cost too much. Yup, I am a greedy cruel person. I say we shouldn't change the money because it would cost too much.
As a SMALL example: The company I work for owns (by my own approximation) at least 8,000 machines with dollar bill validators. A change in the dollar bill that would make it different enough for a blind person to use would instantly make each of those units obsolete.
To one medium sized company, this feel good law would cost $400 x 8,000. That's 3,200,000 dollars in parts. Now add the cost of actually replacing the units and you are at an EASY 4 MILLION dollars. I guarantee you that there would have to be a large number of layoffs, as the company would have to cut costs to try and survive such a non revenue producing expense.
So, a lot of us would be out of work, a lot of businesses would go bankrupt, but YOU would feel good.
Feel good-ism sure does cause a lot of suffering for others, doesn't it?
The article said they weren't looking to change the 1 dollar bill. If you change the other bills, the 1-dollar bill will be distinguishable by NOT having markings.
I'm also betting we could figure out a change that would make the bill physically distinguishable without breaking the machines, maybe by finding a location to put small holes in the bill which you could feel. Doesn't even have to be braille, just one hole for a 5, 2 for a 10, maybe in a different spot for a 20, 50, and 100.
Didn't the recent redesign of the bills require the machines to be upgraded (I don't know, did we redesign the 1 dollar bill, maybe not)?