As you may guess, I'm unhappy about it. In astronomy, almost everyone uses IDL, which is a proprietary, closed-source language. (It also sucks, but that's beside the point.) I think this is bad, because it locks practically the entire research field into a closed platform. (Though GDL is working to be a replacement. I don't know how conformant it is, though.)

Still, I think this is less of a problem than the high-level scientific code. Most of the low-level functionality is pretty simple and (hopefully) much better tested than most scientific codes.