Note that the quote is talking about a well-specified CSV, not any CSV in general. A well-specified CSV would indeed be fairly easy to parse.
RFC-4180
Yes of course there was no recognised standard before that. Just like before Greenwich Meantime there was no recognised standard for universal time coordination ...
The situation in practice is that when people want a “standard” way to do CSV, there is in fact a standard they can use, that does cover most sensible things you’ll want to do with CSV, and addresses the most common corner cases (eg delimeter in field) in a fairly sensible way.
You are free yet to make whatever proprietary extensions or otherwise, at the risk of losing compatibility just as you are with any other standard.