MS Excel has supported CSV that had newlines in fields for a least a decade.

MS Excel also defaults to using /r as the newline char on the OSX version (despite /r being obsolete in OSX since v10.1). It's true that CSV parsers have been around in various forms for a long time but 'complete' implementations in JavaScript haven't been available until recently.

>yet, that is what most csv code does.

Not an excuse, and not really true if we're talking about libraries. Naive one-off implementations of readers maybe.

>heck, ms excell did that until a few versions ago

Nope, Excell, even from 14 years ago has an extensive panel for configuring how (encoding, terminator, etc) your csv file is, and can also handle newlines inside items just fine.