I think ASN.1 was designed for a world with (a) waterfall development and (b) static deployments - ie no over the air updates. Under the circumstances, messing up is simply not an option - hence defining the standard so clearly and for so many use cases.
Today, of course, we treat the entirety of our deployed infrastructure as 'merely' a platform to write code. And not only are experimentation and failure OK, they're positively encouraged. Velocity became important.
You can meaningfully decode any DER encoded ASN.1 structure and serialize it back without any knowledge of the schema. Somewhat surprisingly you cannot do that with all instances of XML documents.
Today, of course, we treat the entirety of our deployed infrastructure as 'merely' a platform to write code. And not only are experimentation and failure OK, they're positively encouraged. Velocity became important.