Excel wasn’t the problem at JP Morgan. There was a reckless culture that thumbed its nose at rules, ignored the guidance of review committees, and tried to sweep things under the rug when they got caught. That would have happened whether the models were written in Excel or Ruby.
If anything, Excel promotes transparency in finance by allowing more people to read the "source" (even the bankers). Cutely named forgotten programmes written in J were a more fecund source of problems.