I think it&#x27;s because 3.0 and 3.1 were basically &quot;we broke everything, it&#x27;s slower, and there are no new compelling features.&quot; The versions after that have been fine, but I think the first two versions were such clunkers that it created a bad schism, and now that there&#x27;s a schism nobody wants to support two languages, so people just stick with 2.7. I think if they had just put some new feature that people had to upgrade for in 3.0, they would have avoided this mess, and people would have grumbled for a few months and adapted.<p>I don&#x27;t think the lesson is &quot;never break compatibility&quot;. The lesson is &quot;don&#x27;t compete with yourself by releasing a product that is actively worse than your current version&quot;