when people say Debian is stable they mean the base platform isn't going to change under you and suddenly a config file doesn't work anymore because Package v2.0 uses a different format.
Yes, that's how a stable release cycle works and not at all specific to Debian. Also, not at all what you said before:
That means not changing broken software to be newer working software.
Obviously it doesn't get updates as quickly as a rolling release would, bit this just isn't true.