In saying that, there are a lot of people I know who read what I call “elevator Braille”. They learn the basic numbers and so on, so that they can tell what the elevator floors are, or they learn just the basics for phone numbers and so on, or the uncontracted Braille. But the people who do use Braille are very reliant on Braille. I carry a slate and stylus like you carry a pen and paper. I use my Braille quite often, and I wouldn't consider myself very proficient.
If that card were sent in Braille, the first thing we would notice is that it's a Braille card. Even if we don't read it, we would certainly pay attention to it, but it wouldn't necessarily give the information you're looking for.
The other thing is that Braille is large. It's really big. On a business card, you only have four lines. There would not be room on that card to put in Braille all the information that's in print.