For reasons I've never been able to understand many sites that have a separate subdomain for news and blogging about the site either do not have any kind of link on the blogging site back to the main site, or do but fail to make it obvious.
In this case the main site is https://www.soup.io/ and the submitted story is to their news/blog site at kitchen.soup.io. Go to the main site and it is clear there what they do.
There is actually a link to that at kitchen.soup.io, but it is easy to miss. It's the small red circled "soup" in the very upper right.
This always bugs on doc sites as well (I think readthedocs based stuff is guilty of this a lot) - no link back to the 'main' site. Forum software often does this too (no link to main site in the forum directory).
I've heard dogma from seo wizards that running the blog on a subdomain yields either negative or positive seo outcome, depending on the phase of the moon.
Also, it could just be the result of some bad ops/sysadmin decisions.
In this case the main site is https://www.soup.io/ and the submitted story is to their news/blog site at kitchen.soup.io. Go to the main site and it is clear there what they do.
There is actually a link to that at kitchen.soup.io, but it is easy to miss. It's the small red circled "soup" in the very upper right.