If their paying customers want something, then that's perhaps a different story, and is governed by whatever agreement (tacit or otherwise) is in place for the purchase.
But if you aren't paying, you aren't owed anything. Not a single thing.
I wished those people could be transferred back to the pre-FOSS days when your disassembler was one of the more critical tools in the toolbox if you wished to fix vendor bugs. I distinctly recall reverse engineering the ROM of a laser printer board to repair a bug that the manufacturer just couldn't be bothered to deal with (Tall-Tree systems Jlaser, I'll never forget). That would have been a lot easier if it had come with source code. These days for me it's either open source or you can keep it.