I have heard that Padma Purana gives wrong descriptions of God such as Vishnu creating Shiva.
Does Padma Purana tell us real or duplicate stories?
I don't think any Puran is BAD..
There are multiple stories about the origins of the Lord vishnu and Lord Shiva.
But when you read any of two puran completely then you will come to a real point that.It is from Sadashiv and Prakriti that Lord Bramha, Vishnu and Rudra are originated or born .
All three Lords are ever present in their esoteric form ,but, they get manifested in different physical worlds in different ways at different times.
As per Shiv Puran after each cycle of creation and destruction the three Lords manifest in different ways. Sometimes it may start with Lord Vishnu, sometimes with Lord Brahma and sometimes with Lord Shiva, sometimes, even differently.
After the latest destruction, Bramha ji came out of a Lotus which grew out of Lord Vishnu's Navel ( now the real esoteric meaning of this story is totally different) and Lord Rudra came out of Lord Bramha's fore head or eyebrow. But, it is also written that before this 'birth' of Lord Shiva and Lord Brahma all three had met each other where the events to follow were known. (The story where Lord Shiva appears in form of infinite tower of energy and then there are more times when they meet before Lord Bramha starts creating Universe). It was one such time that Lord Brahma requested Lord Rudra to be born in the physical universe through him, and therefore, the stories of Lord Rudra coming out of Lord Bramha's eyebrow/tear.
If you label a text as 'bad', just because it does not conform to your views, it only shows your prejudice. Any classification of any text as good or bad should be based on some other valid text, and not on personal belief.
The author of all Puranas is Sri Vyasa himself. The right question one must be asking is why there are conflicting passages in different Puranas, the answer to which one would get from a proper Guru, not from the internet.