On-premise is a sales & tech support minefield. That's why SaaS vendors don't like it. No matter how well documented an on-premise solution is, the customers won't read the docs and when something goes wrong the customer will be unhappy and blame the vendor. And unhappy customers are bad for business.

This is why consumer electronics products have those stickers that warn you you void the warranty by opening up the device. It's because nobody wants to deal with those customers who open up their device, break something, and then demand a replacement because the product is defective.