One of the biggest issues ruby faces is performance. The productivity of the language is undeniable. That is a big reason start-ups so often choose ruby. Eventually Salesforce or Microsoft acquires these ruby start-ups though that the apps run up against enterprise managers who have traditional baroque "cost optimization" incentives. Very few people, especially managers, are comfortable making the argument that paying for more machines is better than paying for more cheaper devs so you see these successful apps rewritten in java, C#, etc. Someone shows execs a chart with costs per user plummeting (usually with a deceptive Y axis), everyone pats each other on the back, and then they lament not being able to find ruby devs when they acquire the next company. I'm hopeful that ruby can close the perf gap enough to slow/stop this weird cycle.