Perfect example of "penny wise, pound foolish"...British origins, so dollars here...
Classic bean counter management that only cares about their bottom line...for that quarter. As their bonuses are based on quarterly performance...
But, that is the way of the corporate world. It is also known as 'financial management' vs 'managing the product'
As for GM's 8 cylinder deactivated to 4 cylinders, depends on which year/era. 
GM's first iteration deactivated the same cylinders all the time when it went down to become a 4 banger. That had the deactivated cylinders not get hot enough and the rings were cold and not sealing. That then pumped engine oil into the cylinder to foul the plugs/valves/etc
Later years/era, the computer managed a rolling deactivation between all cylinders and read that they had balance issues at first.