A financial economist professor once mused that "current phd students are limited in the problems they can solve because they can't program." Of course the programming language he preferred was Fortran. :-)

Excel is the best tool for 80% of what bankers and consultants do. It can middle through the next 10%. The problem is it has just no way to do the last 10%. Either it's too slow or just can't handle the size or computations required.