"Opinionated software" such as with RubyOnRails, defined/strict syntax structures (Python) allow for ease of inter-developer understandings, as less divergence from an established norm is allowed for. This saves time, energy — assuming that persons are willing to cope with the rigors of working within such systems, which may be perceived as being less creative (see Ruby's notion of DeveloperHappiness).
The above likely leads to increased dynamicism (& structural rigidity!) within the labor markets for programmers with those particular skills. Heavier replacement rates according to ease of swapping out one programmer for another, as each are assumed to be working in approximately the same way.