HTTPS stands for HTTP Secure and is a combination of HTTP and SSL/TLS (Secure Sockets Layer/Transport Layer Security) and is used to provide an encrypted connection to a website.
I understand the need for installing SSL certificates and enabling HTTPS on SAAS environments (on-demand) which host public facing websites or enterprise software.
If a customer's software is hosted on their own server infrastructure (on-premises), obviously behind their own corporate firewall, why would they need to have an encrypted connection to their software?