Totally agree, but it takes a really strong product manager to stand up to a sales person with $10K in revenue from an enterprise buyer "if we just add this one feature they want".
The fact that the enterprise buyer doesn't actually need the feature, or could do it easier/cheaper/better is immaterial. A Purchasing Department worker in the enterprise is looking at your product and Product X, and Product X has that feature that some manager somewhere in the purchasing process said they'd like to have. They really like your product, but they can't justify picking it over Product X without that feature.
Telling salesfolk that they have to walk away from the sale they spent months cultivating is hard, and there are often board-level ramifications to doing it. The entire company has to be behind "Keeping it Simple", including the directors and shareholders. This is why these companies (and products) are rare.