If that works out good for you, great. I know that GitHub has every right to do what they think is necessary to maximize shareholder value.
But I don't have to agree with their decisions.
I don't trust Microsoft for pretty much exactly the reasons the parent listed.
I like to look at it from the perspective that they are a for-profit public company and are legally required to maximize shareholder value, and they have every right to do so.
Therefore, any plans I make regarding GitHub will not rely on them being friendly and kind-spirited in any way. If they turn out to be great, I'll just be pleasantly surprised.