They quite often are the owners at least in part.

Salesmen

Offer a free upgrade and a reliable compatibility layer for stuff that won't work on NT6.x and XP will be gone within the year.

Commercial software that my organisation depends on.

It doesn't since neither of those have full Win32 compatibility which is required for a migration. If it was as simple as you pretend then XP would've have disappeared years ago.

Microsoft failed to provide a decent upgrade path to NT6.x. That is most definitely their fault. End users are well aware of the need to upgrade, but when you have 800,000 desktops all running software that doesn't work on any flavour of NT6 then it's not a small problem, it's a hugely expensive problem that even when solved will provide no real improvement in the day to day functioning of the organisation.

I bought a netbook in 2010 that had XP on it so support until 2020 please.

Then why did they make it so difficult to do so?

If they're using Citrix what new OS will they have to learn?

Would the lack of pubic hair be a problem?

If I break into my own house it's not a crime.

No the question is what would you replace Word with in a law firm, given that "Nobody needs office suites anymore"? Do you have an answer to that question?

What would you replace Word with in, for example, a law firm?

No but the systems are backward compatible for this reason.

IT departments also have other things to do as well as doing a major upgrade to core systems that takes several months to do. Stuff that actually makes money for firms and therefore is far easier to justify.