I think I understand the cult part of Excel. And to be honest, Excel is a fantastic tool. I don't think IronCalc can ever replace Excel (a boy can dream though!). But many companies need a spreadsheet of sorts they can embed in their product. Allow me a bit of humour:
> Any sufficiently complicated startup or young company contains an ad hoc, informally-specified, bug-ridden, slow implementation of 10% of Excel.
> Any sufficiently complicated startup or young company contains an ad hoc, informally-specified, bug-ridden, slow implementation of 10% of Excel.
Maybe we can use IronCalc for those cases?