In rhetoric this is what's known as "inoculating the argument", or "inoculation theory". You take a reasonable criticism of what you've said and present a weakened version of what someone might respond with in order to suggest that means that response is invalid.

The thing is though, in this case, you've not really presented a solid argument. All you've said is "Microsoft might be doing terrible things!", which is potentially true, but it's a bad reason to ignore the obviously good things that we can see. What your argument boils down to is that once a company loses your trust they can never get it back regardless of what they do. In which case you're removing yourself from the conversation because you're only ever going to be negative.