> The problem is data access. Nothing more, nothing less. I agree with this, but the problem with global variables is precisely that they make bad data access

> The problem is data access. Nothing more, nothing less. I agree with this, but the problem with global variables is precisely that they make bad data access patterns look easy and natural. Speaking from experience, it’s a lot easier to enforce a “no global variables” rule than explain to a new graduate why you won’t allow them to assign a variable in module X even though it’s OK in module Y.