Accuracy Versus Fluency in English

Why teaching speaking is so difficult? If we compare it to teaching listening skills, where varieties of techniques have been developed since the introduction of the oral communication courses, partly with the aid of new technological devices such as the closed captioning system or mini disk, teaching speaking seems to be far behind.
One reason for this stagnation is that there is no view commonly agreed upon of what successful speaking is. One view is that the speech is thought to be successful as long as the learner can make himself/herself understood no matter how incorrect the language is, while another view insists on correctness in every aspect of language ranging from grammar to pronunciation.