Is the dative really the enemy of the genitive?

Bastian Sick is well known for his books 'Der Dativ ist dem Genitiv sein Tod' (The Dative is the Death of the Genitive) and his column 'Zwiebelfisch' (Onion Fish), which appears in Der Spiegel. When I first read these books and columns as part of my bachelor's thesis, I noticed things that I had overlooked as a private individual, and I asked myself whether everything Bastian Sick was trying to teach me about 'correct' German was actually true. During my research, I came across almost a dozen articles and books by linguists, journalists and grammarians who criticised many of Sick's articles. One article immediately caught my eye. It was by the linguist Vilmos Àgel: 'Bastian Sick und die Grammatik ein ungleiches Duell' (Bastian Sick and grammar: an unequal duel), published in 'Info DaF' in February 2008. I then took a closer look at Sick.