XP has been out of support for 5 years. I get it, IT is hard and expensive, but you've had 5 years (and multiple years leading up to it) to find a solution. At this point it's your fault, not Microsoft's or your software vendor's.
XP is almost 18 years old. If you were running an 18 year old operating system in 2010, you'd have been running Windows 3.11 while everyone else is on Windows 7.
Running XP now is like running Linux Kernel 2.4 today.
If the computer in question is connected to any network, to keep it so out-of-date is simply irresponsible.
The cost and logistics involved in replacing legacy systems trumps the need/inability of highly skilled engineers to protect an old OS.
Other layers might save you, you hope, sometimes. It is still irresponsible. Most actively developed and diligently patched software is bad enough; after EOL it is beyond the pale.
The cost needs to be properly internalized so that getting owned really is more expensive than migrating legacy; today I’d have to agree with you that it isn’t.