Re: I don't get it
Maybe because the licensing conditions you agreed to before any software from Microsoft basically allow Microsoft to pretty much do anything it wants without being accountable for it? As far as I know, the "it's your own fault" clauses in their EULA do not seem to limit themselves to just updates, MS can pretty much do as it pleases.
Could be worth investigating, because this could be undone in the UK under laws that prevent the validity of unfair contract terms. Could be quite fun to do, actually. Now that Max Schrems has his win in court, maybe something new to go after? :)