Most scientists have little or no quality training in software development, but scientific research is increasingly reliant on software. At present, software is a glaring black box in a great deal of research, because very few reviewers have the skills to thoroughly scrutinise it.
A software monoculture always has negative consequences, but fragmentation can be equally problematic in many cases. A reviewer saying "This would be better in R" usually means "I have no chance of understanding your code, because it's not in R". For better or worse, R is currently the statistical computing lingua franca in most fields.
I believe that the scientific method is in real trouble, due largely to the immense complexity of much modern-day research. Scientists have access to immensely powerful analytical and statistical tools, but most lack the training and infrastructural support to use them in a rigorous manner. Bad practices in software and statistics are the norm, rather than the exception; I'm sure most of this is just an honest shortcoming, but I'm equally sure that the lack of CS and stats experience amongst reviewers is a gift to would-be Bogdanovs and Obokatas.
Science has always been a collaborative effort, but I think most fields are in desperate need of greater support from computer scientists and statisticians. Ultimately I would like to see those professions become deeply integrated into all scientific fields, with the expectation that all papers should credit a statistician and (where applicable) a computer scientist. Likewise, editors and reviewers need far closer ties to CS and statistics professionals. Of course, these issues are intertwined with many other problems in funding and peer review.
Until then, the hegemony of R may simply be a price we have to pay for better research in the short-term. A software monoculture at least gives reviewers a fighting chance of spotting issues with software that might affect the validity of results.