The principle is that moderators are encouraged to make decisions; that's why they're moderators. As such, a moderator's close decision goes into effect immediately... that's the way the Stack Exchange software was designed.
As to why that particular question was closed: it was closed as "not constructive" which makes a lot of sense to me. Is the Internet really improved by yet another lengthy conversation about Microsoft and open source? The question is nothing but an invitation to reignite the pointless flame wars which have plenty of other homes. Stack Exchange is for exchanging knowledge.
If you disagree with a closure you can vote to open it, provided you have 3k rep.
That one is borderline so IMHO it could go either way (and already has). I agree with the principle that the determining factor is the type of answers a question is getting, particularly in these borderline cases.
My personal opinion is that one (or more) moderators on PSE who've decided that they are the arbiters instead of the community and are spooked by questions being migrated here from SO. Instead of simply letting the community coalesce around a way of handling these questions, they're being reactionary and defensive. They also seem to take it too personally, rallying the troops to protect their domain. The best moderators have a light touch and a thick skin. At this point, it seems that any question migrated from SO is in danger of being trashed by these mods despite what the community thinks or whether it could be worked into a shape that would be appropriate.
Just another reason for me not to participate here, despite the fact that these are the topics that are of particular interest to me.