Why is Haskell used so little in the industry?

Disagree. Haskell is one of the only truly next-gen languages there is, primarily due to its ambitious design goal of software assurance - basically, it was designed from the ground up to better enable programmers to write error-free code.

The Haskell designers identified the main sources of errors in code as mutable state and side effects (network communication, writing to disk, etc), and then constructed a language that enforced isolation of that code into specific containers, monads.

All code outside monads is guaranteed to be purely functional, referentially transparent, immutable, and side-effect free. It's an idea that seems simple in hindsight, but is rather brilliant.

Add to that Haskell's green-thread concurrency and multicore/cpu parallelism is probably one of the best kept secrets in programming these days, and you've got an amazing language and platform for anyone who takes the time to shift to its paradigm.

>C and C descendants happen to be the primary reason we have not really moved forward any further than where we are right now.

Really? This implies you have some knowledge of what would have happen if C/C-descendants did not exist.

It also implies that C/C-desc adoption was a historical accident, or an idiotic move, instead of something based on very pragmatic decisions. To write a performant program until at least 1990, from a word processor to a game, you needed not only C-level speed but also lots of tricks and twists to your code (ingenuity), most of which were only possible because of the low-level access C provides and the programmer's knowledge of the program's state (so a higher level compiler couldn't easily derive and do the same optimizations for generic programs). And sometimes you even have to drop in assembly. Remember all those 80's games (like Prince of Persia) written in assembly?

So, even if C didn't exist, it would have to be invented (or something much like it). Worse case scenario, we would be using assembly.

After the 90's, with 486's etc, the situation got better, in the sense that we could even afford garbage collection. Still, our expectations got bigger too. Whereas 256 graphics and SID sound on a largely uni-tasking system was good for the eighties (at best you have some expensive Unix workstation and you run X with 4-5 programs loaded, X-eyes included), we now want millions of color, multiple CD-quality sound streams playing, 10-20 heavy programs loaded at once, GPU compositors, streaming audio and video, anti-aliased fonts, etc etc.

So, still, a high level solution feels slow compared to C/C++ when it does today's state of the art (for 10-years ago or yesterday's state of the art, even Python or Javascript is sufficient). Same for UIs (where waiting for the user's actions is the largest slowdown).

As long as you get into the "cpu intensive" or "memory bound" issue, anything but C/C++ seems slow.

(C descendant's like Java/C#/Go etc are also slow --not arguing that. Any multimedia app done in Java, for example, is like a relic from the 90's).

I've also seen an incredible amount of judgmentalism applied to Objective-C's message passing syntax. Does it look foreign to a speaker of classical C? Absolutely. But I found that pressing through the initial shock, I've come to realize that it's just another language syntax, and not particularly hard to either understand or type.