Technical rewrites break functionality all the time. Raymond Chen's blog The Old New Thing is famous because Microsoft are one of the few companies who devote s

Technical rewrites break functionality all the time. Raymond Chen's blog The Old New Thing is famous because Microsoft are one of the few companies who devote significant effort to backwards compatibility of APIs. Keeping things the same has a huge opportunity cost. The reason people don't compliment a redesign of a user experience because the upsides are not immediately obvious. They benefits might be subconscious or change the product in a way that an existing user will take time to understand. The Facebook feed was a classic example of this. At the time Facebook was a directory of profiles and the feed introduced something users weren't explicitly asking for (aggregation of updates from friends). It was was seen as a regression, but it was built off a deep understanding of how the people were engaging with the product. You can hate Facebook for what they've become, but from a business and product perspective that change was enormously successful.