He (the author of the DevBlog) did not just "used COM instead of .NET for the solution", he actually claimed that "There is no .NET API for it".
That makes me wondering if he had ever done ACAD .NET API programming at the time when he wrote it. Well, he probably just post something he wrote long time ago. But, come on, if you post something, shouldn't you at least know what it is talk about. Such a obviously false claim from Autodesk side is laughstock.
I commented on that post and my comment did not live there for a few hours and gone. Someone removed my comment, and unfortunately, he forgot one thing: also removing the post altogether, which may give bad direction for someone who is new to Acad .NET API and trust the information posted in AutoCAD DevBlog.