Why fight it? Make money, not war!
MS cannot be expected to provide security updates to an obsolete OS -- for free. So, MS should begin a program of paid support for Windows XP. Pay $X per year and they will provide updates. Say $10US per seat? People running XP do a cost/benefit analysis, decide on their own when to buy a new OS. In the mean time, MS earns enough money to pay for making the updates.