It has everything to do with creating a product that you sell to a customer who installs it on premise within their environment, and their IT policies require t

It has everything to do with creating a product that you sell to a customer who installs it on premise within their environment, and their IT policies require that software be supported for a certain period of time. Even if you're good at changing their mind some of the time, it's not going to happen every time, so you're basically turning away potential customers, which some people aren't willing to do. This is why it's much better to move away from the shrink-wrap model of delivering software and focus on SaaS only solutions.