I could take a few more minutes to use something that makes me not have to worry about CSV edge cases, or I could just recognize that those cases don't apply to me, throw together an awk line in 20 seconds, and get to the pub early and get a pint or two down before my buds show up.
Who cares about what is better on paper? I have a life to live.
Personally, unless I knew the data, I'd have problems enjoying that pint without worrying about data fields containing e.g. ",":s which my naive script would fail on...
In my experience, files have mixed formats far less often than you might suspect. Generally they were kicked out by another script some other bored bloke who just wants to get home wrote himself. If I don't get the results I'm expecting then I'll investigate but the time I save myself by assuming things will work more than offsets that.
Usually the issues I find are things that invalidate the entire file, and indicate a problem further up the stream. In those cases I'm actually glad my script was not robust.
Sorry for coming in late, but... that argument can motivate the use of simpler tools (here, awk instead of perl) in any situation. :-)
(I didn't mention "mixed formats", I mentioned the specific problems of e.g. ",":s (and possibly '"':s) in CSV. You will find such characters even in e.g. names, especially if entered by hand/ocr.)
Who cares about what is better on paper? I have a life to live.