Tubby Linton
Any landing on 21 will invariably involve touching down deeper than usual unless you get very close to the terrain on the approach.
Err, why? If you follow the approach procedure and fly a constant descent rate crossing 6d at 2000' and then 400ft per nm you will arrive in the right place. Fly the correct airspeed too and if anything, a correctly flown 'steeper' approach has a corresponding touchdown point which is less than 1000ft into the runway. Chambery is again my example, where it even mentions in the briefing notes that the touchdown point due to the steep glideslope is circa 600' (from memory) in from the threshold.
Your theory is incorrect, it would be a shallower approach which would shift the touchdown point further into the runway.
I suspect it is aircraft flying the steeper approach and either flaring too early or having excess airspeed which leads to what you describe.
PP