It really depends. Java isn't bad as server-side software, and there are benefits to using it's runtime. For client-side software though (particularly in 2012-2020), not many commercial PCs could play Minecraft at a decent framerate. Even now, feeding the Java version huge amounts of high-bandwidth memory is the only way to mitigate slowdown, and that still doesn't account for the micro-stuttering that you get when world generation occurs. In the context of Minecraft, it was a pretty obvious mistake. YMMV, but I'd still highly recommend against writing Java software for client-side stuff.
