My estimate is that for every 20 “throwaway Excel,” only one becomes used heavily and required a painful redesign.
Trying to build all these correct from the start is actually inefficient because 1) you don’t know which 20 is right until quite a while in; 2) the idea that better requirements gathering and design is a myth as functionality and use is frequently, in my experience, new based on the spreadsheet and users don’t tell this to the design team; 3) the cost of properly designing all 20 is enormous so trying to pick only the most likely 5 is still expensive and has a decent probability of producing zero useful systems.
So while it sucks to be the engineer cleaning up some yahoo’s hack that got used by the CEO, I’m not sure what the solution is that is best for the enterprise.