Performance is relative, so if the norm is 0.4x, that's the actual "1x" base to just 10x programmers by, even if it's below what a 0.4x programmer could potentially achieve if they really tried.
In other words, if most devs are underperforming due to complacency, lack of motivation, etc., that should also factor in in the 10x programmer calculation.
So, 10x doesn't have to be "10x as good when both are 100% motivated" just "10x as effective" is enough (even if it's because they are more motivated and not actually more intelligent, knowlegeable etc).