It's actually not quite the pronunciation, since bikkie = [bƏki] whereas bietjie = [biki] ... but ja, that should be the idea behind it.
There are all kinds of new spellings surfacing these days, largely thanks to SMS's and Facebook. It seems common in that school of spelling to replace "ie" with "i" and "tjie" with "kie", which I'm pretty sure is what the original "ons skryf soos ons praat" guys would have liked.
Their opposition wanted to keep the spelling Dutch, so eventually they settled for a compromise. The main reason we have the same letters representing different sounds, like how "d" in "land" and "t" in "plaat" are said in the same way, is so that different forms of the words and words derived from them will still make sense - e.g. "land" isn't spelled "lant" because of the spelling of "lande", "landelike", etc., where the "d" does get voiced. In other words, because of "gelykvormigheid" - similarity.
...And so ends my monologue.