In my opinion, the reason is that Amazon, Facebook et al know their users will not receive training or persevere with poor UX or an unintuitive UI. Therefore, t

In my opinion, the reason is that Amazon, Facebook et al know their users will not receive training or persevere with poor UX or an unintuitive UI. Therefore, they have to design good software in order to be competitive. On the other hand enterprise software implementations always include a business change element which involves lots of communication and training, especially for key users. Therefore there is less obligation for vendors to build intuitive solutions.