Personally I haven't used Matlab since college (EE), and I haven't really done those EE things since then. But man, Matlab was indispensable (control loop design, system identification, all sorts of signal processing and E&M stuff).

One of the best things about Matlab was that it had an absolutely enormous library of tools, I could reasonably do everything I wanted, and more importantly, all the notation and convention matched what was used in EE, so I could easily translate whitepapers, and my own and others' calculations into code.

In scientific computing, each disciple has their own preferred way of writing things, so a system identification problem might be stated completely differently by a power engineer, a communications engineer, and a physicist, and deciphering each others' formulas and notations often is just as difficult as understanding the core point of the paper.

That's why a lot of math packages, which were written by academic physicists for other physicists were essentially impossible to use for EEs, and Matlab actually adopting the EE conventions was a godsend, even if it was proprietary.

As a programming language, I didn't like/hate it that much, I guess if I tried to develop an application suite in it like many others did, I'd have had an awful time, but for the simple stuff (in terms of programming) I did with it, it was fine.