Slight counter point re: ruby, I complain A LOT about ruby's and the communities tendency to monkey patch everything. It's a dangerous practice that needs to be REALLY well thought out. just like C++ and the operator overloading, I've had bad and good experiences with both. I don't think they need to be removed from the languages but I do think good experienced developers should loudly and quite often proclaim the dangers of over use.
I think it comes down to culture, not language features.
Objective-C allows much the same monkey-patching craziness as Ruby, but the feature is almost always used to just add additional convenience methods to system classes in a fairly safe and sane manner.
You can do much worse (and I certainly have), but it's pretty rare.
Same and possibly more so in Python. Monkey patching is regarded as a last resort in clever libraries that need to do things that would be impossible any other way. They are generally clearly signposted as 'smelly but unavoidable'.
I agree, I'm a python/django developer in my day job and a ObjC/iOS at home. Both are just a easy to monkey patch as ruby but it's much less used. It's one of the reasons I prefer python to ruby.
