Why is accidently spelled accidentally?

Friend: Stacked suffixes.

Me:ah yes, I see. But, like me, do most people actually say accidently, not accidentally? And say incidently, not incidentally? Spelling should catch up with usage. Or am I in a minority of one, and do I need to relearn how to say those words?

Friend: Chomsky would say English spelling is only partly phonic and also represents underlying form. "accidentally" is a noun turned into an adjective turned yet again into an adverb, and the spelling reflects the complexity of that underlying form. You needn't pronounce the "a" any more than you need to pronounce the apostrophe I just used in "needn't". It's there to represent form, not sound.

Friend continues: But I prefer descriptive to prescriptive linguistics. There's an unending tension in English spelling between those two functions, and spelling reform has always lagged behind the audible evolution of the language.

Me: I agree. I remember that when I was a boy the Chicago Tribune was known for using simplified spelling to match pronunciation. The situation today: The spell checker for Open Office Text accepts both though and tho, does not accept altho for although or thru for through, and accepts the reform spellings catalog and donut and rejects the old spellings catalogue and doughnut. Dictionary.com accepts all of those spellings, calling tho, altho, and thru informal simplified spellings and indicating by prominence of font that catalog and donut are the preferred spellings. In olden times the ugh in though and doughnut, the gue in catalogue, and so on were pronounced as a bit of a guttural sound in the back of the throat. See also http://en.wikipedia.org/wiki/English_language_spelling_reform I like options -- to be able to write thru when I want to be efficient, modern, and logical and to write through when I want to be leisurely, old fashioned, and connected to history. Is it time for "Don't laf at my cof" to be as acceptable spellings as "Don't laugh at my cough"? Incidently the dictionary.com pronunciation audio for incidentally gives both pronunciations.

Me continuing: I just learned that it's guttural, not gutteral.