If there were only one implementation for ASN.1 people would decry that whatever that implementation does effectively becomes the standard, and people would be clamoring to write a second implementation.

Ok, but there are many implementations. And the ASN.1 specs are really clear and readable (once you have a mental model of them).

Yes, which is why the contrast with monoculture is interesting. Hence my original comment.

Ah, I see. Thanks.