What you’re saying amounts to something of a No True Scotsman fallacy... “no _real_ monorepo would limit different projects from using individualized tooling if needed...” Yet that limitation suspiciously coexists with monorepo tooling frequently, and does not frequently coexist with polyrepo tooling.
This is the (wrong) assumption. Like I said, there's nothing about a monorepo that "begets" draconian policy. Your anecdotal experience is not a rule. The monorepo I work with doesn't have draconian policies about how tooling must work. There are apis and recommended tools, and if those don't fit your needs (which is unusual), the teams that maintain those tools are willing to support your uses, but if not, you're also free to hack yourself something that works. Writing additional pre-commit hooks is encouraged.
> What you’re saying amounts to something of a No True Scotsman fallacy
Again, no. Certainly monorepos can do this. They're still real monorepos. But polyrepos can too. They're still polyrepos. Its orthogonal.
I’d flip it around and say instead that you are assuming the properties by which to compare the two approaches ought to be properties that are roughly like “first principles” and that no first principles difference really exists between them in terms of limiting what you can do.
But this is the wrong way to look at it because, pragmatically, it’s simply just not the sociological phenomenon that actually happens as a side effect in terms of the practical result. Who cares if there’s a first principles reason for them to be different in terms of effectiveness? I certainly don’t— they just are different in terms of effectiveness.
Correlation (and a weak one at that) is not causation.
I can just as easily suggest that monopolicies beget monorepos, and that indeed makes a lot more sense. Its easier to enforce global standards when there's a single repo. So companies who wish to enforce draconian standards may move in that direction. That says nothing about companies that don't wish to enforce draconian standards though.
In “The Beginning of Infinity,” physicist David Deutsch makes a point like this about styles of government. Deutsch suggests the defining characteristic of a good governmental system should not be whether it consistently produces good policies, but instead that there is an extremely low-cost barrier to removing bad policies once it becomes clear they are bad.
Thinking this way, if monorepos permit a situation where there are monopolicies about allowed languages, allowed deployment tooling, etc., and those policies cannot be quickly discarded when it becomes clear they are bad for a certain business goal, then this is perfectly good reason to disfavor monorepos regardless of whether they cause the bad policies.
I think your responses continue to miss the point because you’re talking about correlation and causation as if it matters in a situation like this: but it precisely doesn’t matter.
If a tool doesn’t actively prevent certain policy failure modes (even if it does not cause anyone to choose a bad policy), that is a relative failure of the tool.
Contrasting with polyrepos where it is quite harder to enforce failed monopolicy ideas is one area where polyrepos are a better tool: to misuse polyrepos policy-wise you have to go way out of your way and add a lot of draconian policy enforcement tooling that often can still be circumvented. Those inherent barriers are a good thing that monorepos don’t have.
Separately, I’d also say that the political failure mode where central IT wants to enforce draconian policies is extremely common, and those types of organizations specifically see a monorepo as a tool of (their desired) oppression and control.
Since the base rate of occurrence of horrible companies is super high among all companies, it probably does mean that P(bad | monorepo) is pretty high conditional evidence of a bad workplace culture.