[anonoholic]

> an em-dash works just a well without any of the pretense [of the semicolon]

The author makes a clear distinction between the semicolon and the em-dash.

> And using them to separate list items which themselves contain commas is asking the reader to do too much work

The article is specifically about prose, and at no point suggest using semicolons for lists, although I think you overstate the difficulty in parsing your first example.