You'll have to admit that XML is a very good exchange standard: it allows you to specify the encoding of information, it get rid of line ending problems, it is reasonably sef-documented and quite human legible. If all else fails you can always fire up vi and figure out what's in the file you just received.
I know CSV is somewhat self documented if you include column headers but it is still easier to have the name of the field right around the field, even in the middle of 2 Mb of data than to have to go back to the beginning of the file, read the headers and figure out in which column you are. Plus some CSV files are pretty ugly. I just had to process the export of an Access DB that included multi-line fields that was a real pain to parse: there was no special end of record marker so Text::CSV_XS could not read records properly. An XML export would have solved this problem.
Plus of course the hype factor makes it way kewler for management to say they're sending XML than CSV. Maybe tilly should start a W3C working group on CSV ;--)