First, let me start by saying I'm a day-to-day Ruby developer and I absolutely love the language. That said, there are things besides the speed that prevent the acceptance of Ruby among people:
* No static type checking, potentially resulting in more bugs
* Ease of monkey-patching, potentially resulting in insecurities
* Rampant use of hash-as-arguments, resulting in method definitions that don't actually define their arguments (though Ruby 2.0 fixes this with named parameters, it's still a common pattern)
* Heavy use of symbols, which some people see as the moral equivalent of magic strings
I personally think all of these arguments are bunk except for the over-use of hash-as-arguments even in Ruby 2.0. But some people give them credence.
* No static type checking, potentially resulting in more bugs * Ease of monkey-patching, potentially resulting in insecurities * Rampant use of hash-as-arguments, resulting in method definitions that don't actually define their arguments (though Ruby 2.0 fixes this with named parameters, it's still a common pattern) * Heavy use of symbols, which some people see as the moral equivalent of magic strings
I personally think all of these arguments are bunk except for the over-use of hash-as-arguments even in Ruby 2.0. But some people give them credence.