First, I doubt that Finnish spelling is as complex as English.
Second, I was exposed to letters in kindergarten, then started reading words in the middle of 1st grade, just like everyone else in my 1st grade class (the ones who could not were held back [OK, the one person flunked]). Before that (reading from "Tip", our school's equivalent of the more famous "Dick and Jane" books), the closest that we got to reading in the Fall half of 1st grade was the teacher trying to tell me that a bucket started with the letter "p" and was pronounced "pail" even though there was no champagne bottle in it (she didn't like it when I used that very point, for some reason).
(For the non-US, kindergarten was a half-day grade zero that exposed children to letters, digits, minimal socialization, and most importantly naps when we were not sleepy. Nowadays, most children have a grade -1 called "pre-school" as well, ignoring the question of whether they have had day care from infancy because their complete set of parental units had to work)
Third, why are we discussing methods of teaching English in the US when the article is whether Germany is raising a generation of illiterates? Is there a slashdot.org.de to which this should have been limited? Or should we also discuss here whether Chairman Mao's decision to drastically simplify Chinese orthography from historical Chinese is designed to produce a nation of illiterates, or is it just NewSpeak (from 1984), since modern PRC Chinese will be unable to read anything from before the change or anything written by Chinese writers in Hong Kong, Taiwan, or the Chinese Diaspora?