Can you give an example where a cutting edge research is done using something other than Python or MatLab? The only exception is Facebook using Torch. 
In fact, Python dominance in DL is not just my opinion. Even Java devs admit it while trying to justify using Java for DL [1]:
&quot;We’re often asked why we chose to implement an open-source deep-learning project in Java, when so much of the deep-learning community is focused on Python.&quot;
[1] <a href="http:&#x2F;&#x2F;deeplearning4j.org&#x2F;compare-dl4j-torch7-pylearn.html" rel="nofollow">http:&#x2F;&#x2F;deeplearning4j.org&#x2F;compare-dl4j-torch7-pylearn.html</a>