90%+ of his posts contain a link to this low-quality news site. None of them contains further text.

It is very well imaginable that it is his site and that he's trying to get a bit of revenue from visitors.

When owning a site which doesn't provide anything special and news only being copied, you'll need to spam your link to get visitors.
Only good services/sites (which offer something special / unique) do receive visitors without begging by spamming the URL everywhere..