You ask why does Mr. Siegert write semi-scientific publications (sometimes also called: popular science)?
Well, since as a scientist he not only wants to serve the scientific community but also to inspire and thrill the broader public with science. So,  he takes the opportunity to write so-called popular science articles from time to time. Of course, these are not highly scientific articles, and the journals in which they are published vary widely regarding their target group and quality. But nonetheless it is a pleasure to Mr. Siegert to share science a little more directly to people "outside" and to bring research findings closer to society. Because science is for everyone!