What does drain cleaner do to hair?

The reason I ask is because the drain in our shower was badly clogged. We used off the shelf drain cleaner and it did not help. We ended up using the whole bottle and the clog did not budge. I bought a snake and it did not help either. I ended up having to pull the trap apart. I found what looked like little balls of jell. I am wondering if that was the result of the drain cleaner and hair or is somebody butting stuff down the drain that they shouldn't