This one hits the nail on the head, and the reason why not just Microsoft, but a lot of large software players are not incentivized to create better software.
At the end of the day, people like power, to make money, and the people at Microsoft are no exception. And businesses are businesses, enterprises to make money, not altruistic benefactors of humanity, or optimizers of a specific domain, like software. So what business will do are their original thing AND business tactics, and the larger the business, the more tactics they have to employ, otherwise they won't be as large, or even simply won't be, at all. So, on the top, it's all ruthless business tactics. As Microsoft is a large player for a long time, they have quite the rep sheet[0], but they are not unique in doing this. It's the name of the game.