It's not that corps aren't on board - it's that corps never are on board with a new version of Windows until way down the line. Many skip a generation too. This makes sense - a: it's better to wait for fixes and b: it's a big investment in product and training (if you're talking about 1000's of seats).
What mojave is all about is
perception that Vista is a bad product - because (hand on heart) it really isn't. It's solid, reliable and does quite a lot of things a whole lot better than it's predecessor. What really did for it though was the new driver model and the inabilty of large third parties to get their drivers working. The former was a damn good technical decision, but as it turned out a bad political one. The knock on effect will be that Seven, when it launches, will probably use the same (mature) Vista drivers and everybody will go "oohhh it's much better than Vista was!". Sigh.
I don't object to people sticking to XP - what i object to is ill-informed ****e being posted about Vista. Mojave exposed ignorance. Nothing more or less. Whether that's also willful is another matter - because
that's stupid. The bottom line is: XP is a good OS, and so's Vista (in fact, it's better). The sooner the latter becomes accepted by some the better (and that's not me pointing a finger so don't have a benny).
Yes MS would love you to upgrade - it makes them cash after all - but I don't want you to. It's up to you. Just don't force me to read how terrible Vista is unless you can substantiate that opinion versus "omfg vista iz sooooo ****tttteee"
To be clear - there are perfectly *good* reasons for not upgrading - cost, "it does the job", there's no Vista drivers for my steam-driven printer from the early 1900's etc. It's down to personal decision

Oui?