GA pilot reported that while still on the runway after landing; another aircraft landed on the same runway. Reportedly; the other aircraft is from a skydiving operation that does not conduct operations in a safe manner.

Narrative

I am writing this report to describe a runway incursion that occurred at approximately XA:30am local time at the non-towered airport ZZZ. At the time of the incident; I was flying a Citabria when Aircraft Y with call sign X operated by Company X (a skydiving operation based at ZZZ) proceeded to land on ZZZ;s XXXX foot long Runway XX while I was taxing down Runway XX to exit the runway at the last taxiway. I flew a straight-in approach for Runway XX. I made three radio calls on UNICOM during my approach. I made my first announcement on UNICOM when I was 5 nm to the east. I then made a second announcement when I was 3 nm to the east. Both times I announced that I was planning a straight-in approach for Runway XX. Shortly after my second radio call; Aircraft Y announced on UNICOM that it was on a right base for landing Runway XX. (Company X aircraft fly a non-standard traffic pattern that enters the standard traffic pattern on a high right base for Runway XX. They start their approach from XX;000 ft MSL in a continuous right turn with a high rate of descent.) I made a third and final announcement on UNICOM when I was on a 1 nm short final for Runway XX and had the landing jumpers in sight. (All jumpers landed prior to my arrival; standard practice at ZZZ involves simultaneous aircraft takeoff or landing operations alongside landing jumpers.) Immediately after my third radio call; Aircraft Y announced that it was on a 2 nm final for landing Runway XX. I proceeded to make an uneventful landing at ZZZ with the expectation that the landing traffic behind me (Aircraft Y); would adjust as necessary to guarantee safe and proper landing separation. I was wrong. As I exited Runway XX at the last taxiway; I looked to my left and saw that Aircraft Y had landed on Runway XX before I had exited the runway area. At the time; I estimated there was less than 600 ft of separation between the tail of my aircraft and Aircraft Y. As I announced on UNICOM that I was clear of Runway XX and planning to taxi east; Aircraft Y had stopped on the runway adjacent to the previous runway exit (approximately 400 ft in front of me). Aircraft Y then waited for me to taxi past before exiting the runway. In the writer's opinion; Company X is exhibiting a pattern of reckless and dangerous flying that deliberately and needlessly places aircraft and others at ZZZ in harm's way. This is evidenced; for example; by their use of non-standard traffic patterns; poor oversight; and failure to maintain safe separation relative to other landing traffic. Maybe it is time for Company X to pause for a safety standdown and operational review.