Question about subdomains

I'm new to SEO, so sorry for the stupid question. For what I've learned subdomains doesn't have the authority of the main domain, so they have DA 1 and PA 1. So why some web 2.0 subdomains have already good DA and PA without links pointing to them? At the same time, TF and CF are both at 0.

Two examples:
https://interbilgi.eu-gb.mybluemix.net/
https://ciao.wordpress.com/

The first one has DA 72 and PA 33, but TF 0 and CF 0. It has only 1 no-follow link.
Instead, the second has DA 1 and PA 1 and obviously TF 0 and CF 0. It has 0 links.

Is it only a MOZ error, or the metrics are real?

Subdomains do inherit an authority of the main domain to some extent. The stronger the root domain, the more will subdomains inherit. So if you have 200 RD site and make a subdomain on it, it will do fuckall.

If you make Tumblr subdomain, where root site has almost 2 million referring domains, it will show.

Also, MOZ is bullshit, don't pay any attention to it.

Nargil said:

Subdomains do inherit an authority of the main domain to some extent. The stronger the root domain, the more will subdomains inherit. So if you have 200 RD site and make a subdomain on it, it will do fuckall.

If you make Tumblr subdomain, where root site has almost 2 million referring domains, it will show.

Also, MOZ is bullshit, don't pay any attention to it.

Click to expand...

https://www.blackhatworld.com/seo/t...ed-tumblr-has-lower-da-but-higher-pa.1250741/

Please help sir