> I'm sure the massive savings on license costs also make it attractive.
I remember shelling out $60 for a true license of Matlab while in college. I remember thinking, "well you're an engineer now, and this cost is part of that", even thugh it felt like a small fortune. But official licensed version required you to insert the CD into the computer every time you used it, so I gave up a got the pirated version instead.
If you get the commercial version out of college it is thousands of dollars for base and thousands for each "toolbox". Want to have database functionality? Thousands of dollars, optimization functions? Thousands of dollars.
That might be worth it for national labs that like how the native IDE, plotting, GUI, widgets, ability to put into commercial projects (they've secured licensing for the math solvers for you)...etc. It is all better integrated than Python even with it's nice Spyder IDE.
95% SciPy, NumPy and Spyder. I'm sure the massive savings on license costs also make it attractive.