As a developer I dislike "build all things even if they don't neatly fit in the system". I would like product people to come up with features that fit in and are thought out. It makes my work harder :)

But at the same time I agree if we don't build it, we won't have customers and unfortunately keeping/geetting new customers is not exact science.

In the end important part is to get rid of stuff that was build for big fish customer once they stop being customer because it keeps living in code base and after years no one remembers why that stuff is still there.