I don't know Microsoft's motives, but instead of thinking that these are purely selfish motivations on Microsoft's part, we should realize that alliances are ways that businesses, even fierce competitors, can benefit from working together. Giving power to others makes us stronger. Power is a loose cannon in the world. We too often see the power of having a singular focus and misinterpret this exclusiveness as the key to power. Those who have power would benefit from getting perspective on power.
Competition is fun and through competition usually everyone benefits.
But in the end we are all on the same team. We all need our incomes and investment incomes to put food on our table, build homes, get educated, retire, protect our health, improve the quality of our lives, and make our nation strong. We all have a common goal and competition can help us attain our goals. At some level we can all work together to make each other powerful. Leadership is the primary means of properly controlling power, whether it is through God, organizations such as political states or lobbying groups, or through our own leadership, we have the responsibility to stand up for ourselves, and for those who are powerless because they have no other way to prevent domination by others.