Dick, do you write out music notation using a computer? If you only write it out by hand on manuscript paper then you probably have no need of ABC (although it is a useful shorthand for jotting music down). If you already use a music-writing computer program then there is probably no need to learn another system.

Don't think of ABC just in terms of the text language. It is part of a package which includes programs to render the text as conventional notation or to play it back. This is how most people use it, to write music notation and hear how it sounds. Being able to read and write ABC without a computer is a useful bonus, but is not how most people use it.

However by ignoring ABC you are missing out on the vast library of tunes on the internet in ABC format. Like it or not, it has become the de facto standard for sharing folk tunes. If you use another program you may be able to import ABC into it to render it as notation, or you can use an online converter such as this one.

http://www.mandolintab.net/abcconverter.php

Even if you don't feel a need to learn ABC yourself, don't dismiss it.