"But I can't make this work unless I squash the competition by abusing my monopoly" is not a good argument for allowing it to happen, even if it were true here. The alternative is not to have no operating system, but to have a healthy market of other, possibly smaller, likely more operating systems instead.
In real life more operating systems means crappier software because now developers need to create versions for each one in order to be profitable, and not the "vast array on awesome options" open source enthusiasts would like to imagine.
It's a constant tension. In the real world single party government is more efficient than multiparty democracy. But most of the world hasn't clamored for single party rule unless it's their personalo preferred party
