Code:
True but I think he was meaning that for the airline it is less revenue and profit effective.
For example, LH could have 120y+5C booked on a flight for which it would suit the Boeing jets more than an A320 as it would maximise the seating capacity much more. Also, if there was demand for say 150Y+10C (again, numbers out of my head), the A321 would be more appropriate. The same works for cargo.
This way the airline is fixed with up to 162 (all Y) seats and a set cargo limit.
Just my interpretation anyway.
But that relies on other routes and often it only works when the scenario's of 2 or more routes match. Sure, the flexibility is a good thing but it's only one side of the story and if the LH aircraft is needed somewhere else or if there are cost savings by using the bmi (and i'm not talking nightstops-this is often insignificant) then LH management must see it as outweighing said flexibility.