Because writing an Excel clone which is "good enough" is really, really hard work, takes a really long time and you probably won't get away with "Let's do 80% in version 1 and then optimize" - People expect Excel. Not Excel lite. Especially if they have to pay for it.
I’m not saying it’s easy, but in an age of so much disruption it’s honestly amazing how Excel continues to dominate. And I say this as someone who spends most of my waking hours in Excel...
