I like the idea of processes dumping structured objects: pipes are rather often used for the processing of structured data, and while tabulated output certainly makes it easier, we still end up effectively using constants: cut to the third column, sort the first 10 characters, and print the first four lines.

This method is fragile when given diverse input: what if the columns could themselves contain tabs, newlines, or even nul bytes?

Passing objects as binary blobs, on the other hand, doesn't allow for ease of display or interoperability with other tools that don't support whatever format they happen to be. This, of course, can be rectified with a smart shell with pretty-print for columnar data (insofar as a shell could be charged with data parsing; you may imagine an implicit |dprint at the end of each command line that outputs blobs).

I'd also be interested in seeing a utility that took "old-format" columnar data and generated structured objects from it, of course, with the above format caveats.