I don't need a huge pile of fancy features that I can easily write myself. I just need something minimal that works for retro graphics. I am prepared to use some kind of OpenCL wrapper from Java or write my own software 3D renderer from scratch in C++14 to get rid of as many bad dependencies as possible.

Both SDL and SFML may randomly crash during install because of broken dependencies on Ubuntu. I cannot expect the end user to compile dependencies from source or fix broken OpenGL drivers in Linux which is the current praxis for Linux installations.

I do not trust OpenGL nor anything built on top of OpenGL because it is not a real standard when there is no driver certification.

Vulkan is not ready yet as the drivers are few and buggy.

Is there any other platform than Java that has decent performance and can be installed easily on Linux?

No problems at all with SDL/C++/OpenGL. I develop on Ubuntu but users use all Linux flavours.

If you value 466 points go with Vulkan.

I will just stick to Java then and live without userdefined value types.

Regarding OpenGL, it is a work damage from having seen it malfunction hundreds of times in the real world. Lobotomy might cure me from what I have seen buggy OpenGL drivers do to correct code. My daytime job as a firmware developer for hardware producers is mostly to go around bugs in OpenGL drivers so I would prefer not to deal with that when I get home. Even if I would test my games on 20 different OpenGL drivers which is beyond my budget, the next driver version would still break anything slightly complex and require further maintenance. I guarantee you that all your OpenGL games are broken on some driver even if you manage to follow convention to 100%.