Commercial closed source loses because of the profit motive to cut corners and make anti-features. Plus little to no independent peer review. Also legacy stuff can’t just be recompiled or ported by anyone, so ABI has to be stable for a long time. Even new stuff, can’t be all compiled to the same one version of every lib, so basically ever program has it’s own version each lib it uses.

Plus they have a big user base locked in, so they have to take whatever they are given. So motivation to be good is low.

Just so many reasons!