Closed, proprietary code is way, way worse.

Good programmers are ashamed to push anything less than good (at least in their own opinion) to popular public repos. Some of those same pedantic programmers have no problem pushing crap in enterprise repos, and feel absolved because they are pushed to focus on deadlines, new features, and refactoring is very rarely planned for. I did and managed a lot of corporate software development in companies big and small, and did my fair bit of M&As and looked at codebases of successful companies. I dont ever recall feeling impressed. And I am regularly impressed by the aesthetic qualities of popular open source packages. I think commercial code is mostly shit, with the exception of regulated, serious industries (power, space, flight, etc.).

Open source is much better. Closed source is mostly considered 'done' as long as it just works.

One is a 'craft,' the other is 'survival for delivery.'

To elaborate a bit more: open source is about 'symbolic capital' — it's about building a reputation that says, 'I can write code at this level.'

Commercial closed source, on the other hand, is about 'I need to make money by writing this.'

Generally, open source projects tend to have less code written over time, especially when the contributors aren't depending on it for their livelihood. But with commercial closed source, it's not uncommon to have to write 60,000 lines of code per month.

On top of that, open source rarely has to deal with requirements changing dramatically mid-development. With closed source, requirements often shift from the original plan, and you end up compromising code quality just to meet those changing specs. As a result, if you're comparing purely in terms of logical completeness, open source tends to be better.

For example, singletons are rarely used in modern open source, but they're still pretty common in commercial code these days.