Based on my (limited) experience. (Learned it for the sake of learning it, thought it was fun to work with, not considering using it for any serious projects.)

Based on my (limited) experience. (Learned it for the sake of learning it, thought it was fun to work with, not considering using it for any serious projects.): I think it's similar to the reason why DSP's aren't very popular compared to general-purpose CPUs for most tasks. It's a very specialized tool, designed to solve a very specialized problem. If you don't have that problem, it's not a practical choice because it's more difficult to use and often ill-suited to more common problems. I'm sure plenty of others have mentioned strings already. Even if you do have that problem, but only a little bit, it might not be a practical choice. There are a lot of tasks where a DSP might perform better but a general-purpose CPU's still preferable because it's good enough, and the skills necessary to work with one are more common. The story's similar for choice of programming language in many applications that require concurrency and fault tolerance, but not to any particularly great extent.