why should indexer/searcher be coupled to email files in particular, instead of dispatching on MIME types? why should the datamodel be something ad-hoc instead

why should indexer/searcher be coupled to email files in particular, instead of dispatching on MIME types? why should the datamodel be something ad-hoc instead of RDF? http://blog.whats-your.name/post/2011/02/14/sifting-thru-your-IRC-logs-w/-examine http://blog.whats-your.name/post/2011/02/14/sifting-thru-you...