[tm4n]

This still seems rather unfair, why are other proprietary operating systems not obliged to incorporate a similar feature? It's Microsoft own operating system and they should be allowed to incorporate whatever piece of software they'd like, albeit to a reasonable extent.

On the other hand, I do find it weird there are no repercussions like this for Windows' new secure boot "feature".

[masklinn]

> why are other proprietary operating systems not obliged to incorporate a similar feature?

Because "proprietary" is irrelevant, the operative word relevant to the original judgement was "monopoly". And more precisely abuse of a natural monopoly.

> It's Microsoft own operating system and they should be allowed to incorporate whatever piece of software they'd like, albeit to a reasonable extent.

If they were sitting at a 10% desktop OS market share that would be the case. But over the last ~150 years, natural monopolies have come to be seen as too dangerous (due to their ability to leverage an essentially impregnable stronghold into dominance in other domains through "legal" market distortions) to be left to play by the normal rules, so many first-world countries have additional rules for monopolistic entities to follow.

In the EU, companies in dominant positions have "a special responsibility not to allow [their] conduct to impair competition on the common market".