Hi Erik ,
You are right about the programming and advanced descriptions of the chip .
But including a simple datasheet which includes absolute maximum rating and normal working conditions and pin descriptions is mandatory ,why not tell the customer what does this chip do?
i.eg. i wonder how sony and other manufactureres have access to these STKxxxx integrated ampilifer circuits datasheet but we as people - considering these chips are available in market - don't have access to them , i have seen some of the datasheets of these chips which is scaned from the papaer by some people and made available on the net .

And i always look at every board i get my hands on and search for the datasheet of the chips on it , for commercial product which is mass produced always more than half of the chips have no paper ,even not listed on the manufacturere website !
(Philips and Atmel have had best support til now ,they list most of the parts they produce)