172, performance relates to distance from the threshold.
The height, normally rad alt - wheels, relates to the flare segment of the published distance; TCH - touchdown.
Although different altitudes could change the actual distance achieved, this will not change the published performance.
Re this thread; arguably a low flat approach could extend the flare distance, but the discussion in this case is the height over the road.
Based on the videos most landings appear to be around the visual aiming point, and relative to that, not that many ‘short’. However, these short landings may be being judged with respect to other runway threshold positions, particularly if the alternative runway markings and PAPI positioning are not considered.
The height over the road relates to safety; thus the aircraft position relative to the PAPI (eyeball, flt-deck height over road) might be the only comparison - which we (don't) have. Thus on this runway the approach might not appear unusual to the crew, even with some variability below the PAPI path.