It's not mandatory to have an infinitive after "scheinen", sometimes just an adjectival phrase is enough. However, that usage often sounds somewhat stilted and seems downright wrong to me when it's with just a simple word. For example,
Es scheint problematisch, einfach so anzunehmen, dass ...
(It seems problematic to simply assume that...)
sounds perfectly fine to me, whereas
Das Auto scheint schnell.
(The car seems fast.)
sounds completely off. I feel the same way about the English translations though, so I guess you can just translate "scheinen" with "seem".
Therefore, the highlighted sentence in the Spiegel article doesn't sound completely wrong. It does sound slightly odd to me though, and I think it would have sounded better with "zu sein".