One major selling point of Ruby is the robust ecosystem of high quality, open source libraries which are relevant to the things SaaS companies need to get done.

One major selling point of Ruby is the robust ecosystem of high quality, open source libraries which are relevant to the things SaaS companies need to get done. There's a ton of code you just don't have to write if you stick to Ruby. The fact that "Ruby developers already basically know the Crystal syntax" is a selling point for Crystal, but if people are already evaluating a switch to another programming language, that's just one of many factors that must be considered.