Some of this behavior might be inexperience -- although, considering Microsoft's size and resources, there seems little excuse for such inexperience. But, when Microsoft's ventures into FOSS are so tentative and self-serving, and so full of competitiveness at the expense of cooperation, nobody should be surprised that attitudes about Microsoft never shift. The history between Microsoft and the FOSS community is so long and bitter that it would take years of exemplary behavior for Microsoft to be accepted. As things are, Microsoft's behavior gains it very little behavior -- nor should it.
Of course, there are two efforts that Microsoft could make that almost instantly create trust. It could depose those who have a history of hostility to FOSS like Steve Ballmer, and it could release the code for some of its key products, such as Microsoft Office or Windows. But these changes would be such a vast transformation of Microsoft's internal culture and business model that they are almost inconceivable.
The most that Microsoft seems willing to do is a few exploratory gestures, and these are so half-hearted that they can never be enough. They can only increase the community's skepticism, especially when combined with traditionally aggressive business tactics.
The idea that Microsoft could ever win the trust of the FOSS community is unlikely. Most likely, Microsoft will continue to blunder along like an abusive husband, alternating aggression with efforts at conciliation.
Still, the possibility is worth considering for at least two reasons. First, as Microsoft makes its gestures towards the community, it is worth articulating why they fail, in the unlikely event that people start believing that Microsoft has changed. If Microsoft can benefit from such explanations, so much the better -- although its corporate culture and practices probably make it incapable of taking the advice anyway.
More importantly, with FOSS becoming an increasingly more important part of business technology, we can safely predict that we haven't heard the end of Microsoft's efforts to embrace FOSS. Probably, too, other companies who have been equally hostile to FOSS might try to look or become friendlier.
Under these conditions, it is worth articulating what a genuine change in attitude might consist of, so we can know what we are looking at -- just in case it actually happens one day. And so that meanwhile, we can detect mixed efforts or frauds.