A bumpy landing might feel like pilot error but it's usually a conscious decision made in the cockpit, not an indication of whether the pilot is good at their job.
A hard landing might happen in crosswinds, when the pilot needs to stabilise the aircraft as quickly as possible, or on a short runway, in which case the pilot wants to put the aircraft down early in the touchdown zone to conserve as much of the runway as possible.
Landing on a wet runway runs the risk of the aircraft hydroplaning, skimming its tyres dangerously over the surface of the water without making contact with the tarmac, and that's another reason a pilot might make a positive landing, which could feel quite abrupt in the cabin.
Every aircraft type has its own characteristics, and pilots need hours of training before they can sit in the co-pilot's seat.
When a pilot is new to a particular aircraft type and not completely familiar with how it handles close to the ground, they might also make a firmer than usual landing, just to be on the safe side.