I accept that point regarding ham strength and over the last couple of years have done a lot more work on the deadlift variations. This can be a real problem for cyclists who become quad dominant and ham tight.
Of course the dl work is hip centric and not flexion based. The RDL, for example, obviously doesn't hit the hams in the same way.
Am I right in thinking that working on the hams in this way is a 'movement not found in nature'? Ok, I'm fooling around a little with that but I've always thought that the leg curl machine wasn't really replicated by anything else. You can use a physio ball. You can drag a plate across the floor with your heel. You can use a band. But when do we use the hams like that naturally?
Obviously the big lifts mirror life to a degree (I'm not going to call them functional). Even the maligned bicep curl is a movement we mostly do every day. Perhaps I'm just being obtuse but this has puzzled me for quite a few years and I've only just thought to ask someone.