I see alot of people saying ''just learn the new OS, it's not hard!''. For a ton of buisness changing OS is not about people learning the system but software compatibilty. A huge amount of buisness run 32 bits with 10 year old rigs with a single 1.5 core with 1 or 2 gb of ram. It's also a heavy process, you have to have techs coordonating the transition, synching the software, hardware and employess. Add to that countless hours of beta testing apps and then the nights to do the actual transition.
To top it all off, add the hours of slowed production due to actual learning and all the ''i lost my new password'' or ''how do I open outlook now''.
This ends up being one hell of a burden for a buisness and also factor that this may be the first and/or most significant upgrade a buisness has known. Alot only ever ran XP and just finished 10 years of peace, they are not ''armed'' to ''fight'' that ''war''.
Software compatibility is definitely a concern, but when talking enterprise transitions you plan *years* in advance. This is where extended paid support from Microsoft comes in, it's a program designed to let enterprises pay to continue selective support as a stop-gap until they can finish up that testing and migration that's been in the works for years already and didn't quite make the deadline. It's not intended as a "use it forever" service so they simply don't have to bother with the hassle of updating technology. For the really unique use-cases, there are plenty of workarounds such as secure virtual machine environments. The last company I worked for (a multinational fortune 500 player) still had some people running apps in OS/2 VMs

Those VMs were configured behind a secure citrix portal and never touched the internet. They accessed an internal database and a handful of network printers, nobody was browsing amazon on their OS/2 VM.
If you're an enterprise that didn't take XP EOL seriously and didn't make any plans to migrate, you deserve what you get IMO. It's not like you didn't have a
decade of lead time to start that ship turning. Technology is an ever-changing field, if you put the blinders on and dig your heels in, your business is going to crash and burn. User training and adapting to changes in workflow are key parts of managing a business, they can't just be ignored.