I have added this request to the tracker:
Issue 2144 – Read list of users and groups for Properties dialog from /etc/passwd and /etc/group
You can vote for it there.

Yes, I mean parse them from /etc/passwd.
But maybe you will achieve it with more proper way.

What do you mean by "parse list of available users". Do you mean to parse it from the /etc/passwd? Or something else?

It would be useful to parse list of available users in Properties -> Owner and Group fields.
Maybe it is correct to get list from /etc/passwd
Midnight Commander already has such feature.