When I published my first book, it was in German. My copy editor was fantastic, and it was a pleasure working with her. My German is not quite native, and she found several things on every page to improve upon. She also complemented me on my content in the end by saying that she and her husband had decided to put solar on their roof after reading my book.
When I then published the English edition of that book, the process was chaos. My copy editor made all kinds of haphazard changes. For instance, she did not like to have adverbs stuck in-between the components of a present-perfect verb. So if had written that someone "had also proven" something, when I got her edits back, that passage read "also had proven". Puzzled at the time she had taken to make the necessary changes (this stuff was all over the place for more than 150 pages), I wrote to her and pointed out that my way of doing things is not only perfectly correct, but also more common than the changes she had made -- if you enter "had also proven" (you have to put it in quotation marks in the search field to get the exact wording) in Google, you get some 420,000 hits, whereas "also had proven" only produces around 112,00 hits. She also changed my commas frequently, explaining that it was the publisher's policy to get rid of "unnecessary commas" -- to which I could only respond that I, too, did not like unnecessary commas, which is why I had not used any.
Grammar and spelling rules are set forth in stone in German, and while there are a number of cases that seem unclear, there are not too many to count. And of course, native speakers of German do not by any means get all of the rules right. But there is absolutely no equivalent in German for the kind of nonsense we have about, say, split infinitives -- which the Scottish professor agrees is a non-issue: "the split infinitive has always been grammatical and does not need to be avoided." My sentiments exactly, though I would go one step further and argue that there is actually no such thing as a split infinitive in English. The "to" in our infinitives does not actually belong to the verb at all, but rather to the precedent phrase:
I could prove that if I wanted to.
But I am not going to.
I wouldn't bother trying to.
If we actually had split incentives in English, then the sentences above would probably have to be considered "dangling infinitives" or something to that effect.
Finally, though our Scottish linguist does not mention it in his article, I'd like to mention my personal pet peeve: the avoidance of "they" as the first-person generic pronoun in sentences like, "Everyone has to do their own work." I remember learning that such usage was not correct English in eighth grade, and I remember that everyone in my class thought that this new "rule" was pretty stupid.
It turns out that the insistence on "his" in such cases ("Everyone has to do his own work") is, in fact, quite recent and is the result of the kind of crappy grammar books that our Scottish professor is complaining about. German children naturally produce the equivalent sentence with "his" ("Jeder muß seine eigene Arbeit machen"), and in French there is in fact no difference between his/her, with son/sa relating not to the gender of the person, but of the object possessed ("elle a perdu son chapeau" & "il a perdu son chapeau" mean, respectively, she/he lost her/his hat). But at least speakers of those two languages do not learn a rule that contradicts what they grew up saying and introduces something they have not yet produced.
It would be wonderful if we could toss out all of this he/she nonsense ("everyone has to do his or her own work") and just go back to what we all learned as native speakers.