Instead of the total number of speakers the better metric would be the diversity of the speakers. A language is a better candidate for a lingua franca if its s

Instead of the total number of speakers the better metric would be the diversity of the speakers. A language is a better candidate for a lingua franca if its spoken everywhere a little, than somewhere a lot, e.g. Mandarin. And this is not about cost, but about Bugs in critical infrastructure. I'd get rid of smartphones and unicode in a heartbeat if it meant bug free command line applications, no malware, and medical and infrastructure that doesn't crash. I think its great when non english workplaces require english. It gives people an incentive, because humans are a lazy species. And once you learned it you can use it on your next vacation, your next online encounter, and who knows where. Having computers only do english would have given a similar incentive, and I'm sad we didn't use that opportunity.