LinkedIn, Macmillan and the English language

Most companies that advertise jobs in LinkedIn are leaders in their field, are at the forefront of research, have branches worldwide, answers and solutions for their clients, are at the cutting edge of technology, the best in innovation... or so they say. They try to sell themselves with hype (hoopla) using language that betrays them. La crème de la crème in their industry do not bother to use acceptable English, and often slip into blunders that belie their presentations. Do not be deceived.
Youngsters who usually are half baked culturally and linguistically, are appointed to positions where they show their true colors with a lack of respect for the basic tool: language, the English language in our case.
There are many examples to pick from, but I have chosen Macmillan Education which is shopping around for new employees. "You will be a native speaker level of English (native preferred)..." I guess they mean that the "native speaker" must be born in the UK. It beats me. Macmillan is very innovative in punctuation: "with an understanding of the publishing industry/its customers/its competitors..." The slash instead of a comma is very intriguing. The candidate must have "an understanding of the pedagogical principals of language-learning." Principals? I guess they mean "principles." But they repeat the "principals" a line below: "... an in depth understanding of both language-learning and publishing principals." and they write "in depth" for "in-depth." Only a begginer would confuse "principal" and "principle"... but we are dealing with Macmillan Education, no less. The whole ad is riddled with poor syntax, faulty grammar, senseless matter and phrases, bad punctuation... which shows the copy was not properly vetted. If the writer argues that he meant "principals" he is in for trouble. May I exclaim: "O tempora, o mores"? And further: "Vade retro, Macmillan"?