That's after they had already made billions with Ruby and, BTW, Patrick Collison is still passionate about Ruby and has no plans to drop it even at Stripe's sca

That's after they had already made billions with Ruby and, BTW, Patrick Collison is still passionate about Ruby and has no plans to drop it even at Stripe's scale. No-one says Ruby will cater for all scaling scenarios but it can take you a long way with the advantage of moving quickly and developer happiness. Twitter started with Ruby and nothing stopped them form switching to Scala when the time was right. What is more common than ditching Ruby is splitting-off services to be written in a faster language. Best of both worlds. Your designation of Ruby as an inferior language begs the question inferior to what and inferior by what metric?