Dictionaries have always been descriptive as well as prescriptive in as people consult them and nowadays spellcheckers use them as well. Not every spelling variation makes it as an option into dictionaries (or should make it). Only if it used ALOT (which I don't think applies yet to 'proscriptive').Dictionaries should be descriptive, not proscriptive.
And some general rules (eg, in regard to capitalisation, like restricting the use of all-caps words to abbreviations) are very effective in keeping spelling from developing to many variations.