My boss used to try and make clients understand they could do minor adaptations of their workflows, and adapt a few labels of the product and they’d be done and productive in a few days, and they’d requests weeks of system customisation instead.
Frustrating as a developer that is already slammed, but good for the business overall. But how many times have we all built extremely complex features that never ever get used.
First: I think you guys misunderstand the very nature of business. All customers have problems they want YOU to solve in exchange for money. The rest of the people just don't contact you. It's kind of the "survivorship bias."
Secondly: Within an organization, if a project manager has a budget and is tasked with solving a problem, "let's make IT adapt our systems" is not an acceptable solution. Most of the time all you have is money, not software developers or IT staff. They are hopefully working on their core product and not on billing or sending emails.
Thirdly: Don't underestimate the ongoing support that stems from point two. If you ever make adaptions to someone else's software, you know what's going to happen when there's an incident and you call support: They are going to blame your customization, they are not going to understand your needs or customization and they'll kindly string you along until you fix it yourself using precious staff ressources. It is much easier to let someone else do everything from start to finish and pick up the phone when there's a problem.
Sometimes clients don't know what they want. Sometimes you have to show them. “If I had asked people what they wanted, they would have said faster horses” ~ Henry Ford.