Greatest Java apps

(Though Java versions certainly exist, too.)

It's also worth noting that Minecraft was originally implemented in Java, but, in order to get it running on consoles and mobile, they had to port it to C++. Which doesn't discount how much Java contributed to its early success. (Most importantly, I'm guessing, by making it even feasible in the first place for a single person to implement it in so little time.) But still, the big picture version of the Minecraft story does more to support than challenge the main reason why C++ is considered the language of choice for games development. Because, yes, Java got it off the ground, but it was only a couple years later that they had to port it to C++ in order to access a mass market.

Java was picked because (for the most part) it just works on everybody's machines, it comes by default with a large set of libraries, and it can build standalone executables (great for grading purposes). You don't have to explain why MacOS comes with Python, but you shouldn't use that version of Python. Java of course has its peculiarities, but so does every other language.

And as you say, you won't just be learning Java, you will be learning how to develop software. Over time and with exposure to multiple languages you will find switching between them is possible. You may (will) have preferences but with a solid foundation you can say "I recognize that this is a loop over an array, I don't remember the exact syntax in this language, but I know how to look it up".

I'm not sure what your situation is for a masters, but for the best odds of job searching post-undergrad the best advice I could give is have several projects which you can talk about the implementation specifics (why did you choose this pattern) and the big picture (why did you choose this architecture). For an entry level positions the exact language didn't matter when job searching as long as it was in the ball park.

TL;DR You're going to school to learn computer science and to illustrate those concepts they're going to use Java. That knowledge WILL be transferable to other languages. For maximum value explore and tinker with other languages on the side.

And as a bonus, a lot more of the world runs on Java than you think so it will be valuable to have on your resume.

Also, if you are going to be a React web developer, the theoretical/advanced stuff they teach you in an MS program is likely not going to be relevant at all to your actual career.

Source: current MS CS student.

I'm not sure this applies as strongly in Minecraft's case specifically, because of the critical importance of its modding community to its wild success. Normally it wouldn't matter what language you pick in terms of how popular the game is going to become, except it just so happened that by choosing the JVM they gave the ability to the community to decompile the game and add the content they want. Maybe this wasn't intended and Notch chose Java because it was what he happened to know, but it's my belief that if Minecraft had been written in C++ instead then Mojang would not have the brand recognition it does today. Anecdotally one of my friends tried the RTX version of the game which was rewritten in C++, and his reaction amounted to "it's fine, but there's no mods, so it's irrelevant." And that's in spite of the fact that modded Minecraft is a minefield of incompatibilities between years old versions and can easily consume 10 gigabytes of RAM and millions of extraneous CPU cycles. Nobody cares, because at the end of the day modded Minecraft is the only way they can get the specific experience they want out of a video game, and the only reason this is possible at all, even if it will never be performant, is the JVM.

But that's only because Minecraft is one of the most popular video games in history, and not the kind of thing that a developers for a game nowhere near as successful would worry about before gaining a sizeable audience. What good is a modding system if not many people want to use it? And depending on the game a mod system might not be as warranted, so in those cases the choice of language doesn't matter as much.