Say, can you write a proposal for how this will save oodles of money upgrading IE8 on 10000 machines to IE10, even tho it will brake the internal apps of about 15 different departments? Maybe you can also write 15 separate proposals for them to renew their contracts with the people who originally wrote the apps, and proposals for the cases where the original dev is long gone and we'll need to do a full replacement.
So the excuse is, "But maintaining an important app involves work."? What someone really ought to write is a termination notice.
Anyone that has a large businesses' critical applications tied to decade+ old technology has grossly underperformed in their position. And if they inherited that mess, it was their first priority to clean up after former, horribly inept individual, with the explicit goal of dealing with the elephant in the room. If they still don't have a plan to extricate the business from a miserable position, where it's their job to do so, they're simply not doing their job.
From a tech perspective, the idea of having anything tied to IE8 is a little ridiculous, as anything written at the time should've been spec'd for cross-browser support, or at worst, require minor rendering bugfixes. Everyone knew better by then.
Anyone still asleep at their desk while a company relies on IE6 should be terminated as soon as possible, no questions asked, and preferably never employed in tech again. That's an absurd situation, for which there's no imaginable excuse.