There were several reasons, most of what other people mention here factored in. Matlab was being a PITA to deploy because of the licensing, Octave wasn't match

There were several reasons, most of what other people mention here factored in. Matlab was being a PITA to deploy because of the licensing, Octave wasn't matching it in performance, it's relatively unpleasant to work with, etc. The big reason though is that I was trying to use it "in production" with MCC and it just really wasn't up for the task. It became a nightmare to debug and had major stability issues; I couldn't keep it running for more than a few hours. The logged errors were cryptic null-pointer exceptions from deep down the stack and the input that caused those conditions would run fine upon restarting the process. A real nightmare to deal with. Eventually I realized that I'd spent a solid two days worth of work trying to fix it with no end in sight and decided that splitting off all the logic into a twisted service wrapping NumPy could be done in less time than I was probably going to continue spending messing with Matlab/MCC. Took about a day to do that, and mostly because some of the math was slightly beyond me so I had to use some significant caution. Ran like a dream after that for months.