Well, the only location many programmers nowadays stumble over ASN.1 is in certificates. And ASN.1 parsing from them has a history of massive security issues and results in massive warnings of &quot;do not touch!&quot;.<p>And yes, &quot;good marketing&quot; in the form of readily available and well-documented libraries for the languages we use is a very important factor.<p>I bet the telecom sector has their battle-tested libraries for ASN.1, or at least for the parts they use. Are they open-source? Are they available for all languages wanted? No? Then why would I use ASN.1, just to use a &quot;standard&quot;, if it means using worse code or writing it myself?