Task parallelism is fine with the goroutine model, but not data parallelism, which is just as important if not more so. (Although note that task parallelism depends on having good locking strategies, and having more static checking than Go offers in this department is always nice...)

Why do we use GPUs, for example? Data parallelism. What have all the advances in video/audio codec implementation been the result of? Data parallelism again. What makes hashing fast? You guessed it...