IMO their way of thinking is that it would require too much spending to jump up the table significantly - a level of spending they cannot afford.
They'd need to spend at least 150 mil to get into top 6 - Man U, Man C, Arsenal, Tottenham, Liverpool, Chelsea.
They'd need to spend at least 50 miil to get into top 10 - Everton, Swansea, Southampton, Newcastle.
Then there's the tier they're aiming for - 11th-15th, where no such investment is needed, as long as relegation is not looming. The investment to jump from that 11-15th bracket to 7th-10th is just too big.