As a Rails dev, this made me chuckle, yes, I've put a lot of hours into troubleshooting dev setups. But this is the wrong example. All of these are installed with one line on the terminal. And really, there are far simpler web stacks to pick up without even having to leave Ruby. Sinatra on system Ruby works just fine. All you do is 'gem install sinatra', open up a text editor and go.
Really, the complexity you have to watch out for is the complexity you impose yourself. Choosing the wrong tools for the job or the wrong abstractions. For many applications, Rails is overkill.
On the other hand, 30 year old C code will often compile right out of the box, because the people maintaining them weren't chasing the New Flashy every year.
The modern systems suck in terms of maintainability.