to csv or not to csv

In another forum  Morten Welinder commented:

> The first rule of csv files is "don't use csv files".

That scares me.  In just one of my directories, I just now counted
two dozen .csv files created in the last 24 hours.  A total of 12
megabytes today, just in this one directory.  There are others.

My professional life depends on .csv files that I get from various
sources. Data is available to me in that format, and often no other.

Very often I need to do calculations that can't be done in a spreadsheet,
so I export the data, krunch it using thousands of lines of C++ and/or
perl, and then import it again.

If I'm not supposed to use .csv, what am I supposed to do?  This is a
very serious, non-rhetorical question.  Constructive suggestions would
be welcome.

I have considered reading and writing .gnumeric xml files, but that's
not so easy.

I have considered using the gnumeric introspection features, but they
lack documentation.  And for months now I haven't been able to even
compile those features, so they remain turned off entirely.

Seriously, folks, what am I supposed to do?