Originally Posted by hamallu

In terms of hardware offering it really is down to the fact that most European regional flights are less than 3hrs in length with high fluctuations on C:Y load ratios across different destinations and even times of day, hence the creation of the much loathed flexible CY seat with movable cabin dividers.

Compare this to say QF as you mentioned and you'll see that QF rotates their 738s on much longer sectors that included even DPS and IIRC also SIN once upon a time so having a proper C class seat is vital for fleet commonality. However, at the same time, even QF can be accused of using those dreaded convertible seats, which are found on their 734s and without cabin class dividers at that!!