The not constructive close notification reads:
not constructive
This question is not a good fit to our Q&A format. We expect answers to generally involve facts, references, or specific expertise; this question will likely solicit opinion, debate, arguments, polling, or extended discussion.
We cannot really say that the format “Is doing/behavior X considered acceptable/professional” is not constructive, some of the questions you listed are unsuitable, some are fine and the rest could go either way.
Personally I think the piracy question is at the bottom of the pit, quality wise, it's extremely vague and almost all answers are opinion based, only one answer provides references. It's a good example of exactly what questions we don't want on the Workplace. Aarthi's question on the other hand has enough information for a specific answer, without being too localized. We can't say that it won't attract bad answers, but it will be very easy to identify bad answers if they start appearing, because it gives us enough parameters to judge answers against. The piracy question is purely speculative and it generated a ton of questions, that's always a bad sign.
What is the main difference between them? The piracy question is not about an actual problem the OP is facing, it reads more like a curiosity question than a constructive question. Obviously I have no idea what the OP is facing in real life, but that's irrelevant, we can only go with what they decided to share in their question, trying to imagine what might be going on is not really something we should be doing.
I have absolutely no idea why people keep asking questions that are not about actual problems they are facing, it might be because they are trying to harvest reputation or because they honestly think that the question will be beneficial to others. It doesn't matter, the questions are unsuitable whatever the motivation.
Every time I bring up that questions should be practical, answerable and based on actual problems that you face, people are always quick to respond that their questions are absolutely practical and can happen to everyone. However practical is not the only requirement, questions should be on actual problems you are facing or faced in the past1, not something that you imagine might be a problem. Those questions are more fitting for a discussion forum, and The Workplace is anything but a discussion forum.
All that said, sometimes asking on a practical, actual problem that you face may not be enough, the question might simply be unanswerable, not every question can be answered by a bunch of random people on the internet.
As a rule of thumb on "Is X a normal/acceptable workplace behavior/situation" questions it would be preferable that we didn't have to ask questions like acceptable to whom, by which standards and on what specific industry.
But if there is a well crafted useful question but just because it is based on this line/format, should they be regarded as non-constructive?
Unfortunately the Stack Exchange format and the available tools can't handle everything. Some questions might be well crafted and useful and still not suitable for the site, that's just the way it is. It's true (in theory) that there is a (very) small possibility that we may miss a few great questions only because they don't work well with the format, but in practice we rarely seen that happen. You'll have to remember that the site is part of a family that includes 84 other sites, and every site had similar discussions early on, and at least on the mature sites the decision is always to not let the site become a discussion forum, even if we lose some great discussions in the process.
Lastly, as I already mentioned in a comment, the popularity of a question has nothing to do with whether it's suitable for the site or not. Shog9 put it beautifully in a comment to another Meta question, so I'll just steal it:
There's a reason these sites have two parallel voting systems, one for ranking and the other for moderation. Helps to separate the "bikeshed" voting from that intended to indicate suitability
People tend to flock and up vote trivial questions, no one knows why.
1 In which case, if you solved the problem it would be absolutely fine to provide an answer telling us how you solved it.