One of the hardest things to realize about Stack Exchange is that we are contributors to a site, but we are not the revenue stream for the business model. That lines from the next person to visit the site. Much of the site is designed around this - optimizing the search engine and being the place to go to find the answer to the question (not a forum that has a dozen answers, if you want that, there are many sites that cater to that approach).
For a question to be useful to this business model, it must be something someone wants to come to and see. A question that is only helpful to one person - the one who asked it - adds negligible value to Stack Exchange as a whole. Compare to a question that people do want to come to and see.
As users with a reasonable amount of reputation it is our responsibility to keep the site on topic, and useful to this end. If someone is asking polling question, or a question that doesn't do a good job of explaining itself it needs to be addressed. In many cases, this means closing questions. For some reason, P.SE tends to get a lot of the people looking for help on their career, education, or with very poorly defined questions.
I don't believe that it is fewer questions that are allowed to be asked, but rather that you see more and more of the borderline and on the poor side of borderline.
I will note that I personally have a philosophy of close fast, fix, reopen to try to avoid getting answers to questions that don't work correctly (the polling questions are most notorious for this). I do dismay at the difficulty that people seem to have reading the on topic portion of the help center and those who have the question closed as "too broad" or "primarily opinion based" on Stackoverflow and then reask it here without fixing the underlying problem of too broad or opinion based.
Aside from closing questions, we have the ability to edit them. Transforming a question that isn't a good fit into one that is a good fit (even if it is not the one originally asked, but should have been asked).
To the editing part, consider Java continuous integration with extras and Considerations on which Java version to run in Production which are two examples of questions that I reworked into ones that fit the site. I am sure other people have other examples - I just don't know them off the top of my head.
If there is a question that you believe should be open, please, come into the chat room and people there would be happy to work with you to figure out how a question can be worded so that it can fit properly within the site.
Many times, though, this will involve working with the original asker of the question which can be difficult (there is a surprisingly large number of users who ask a question and never revisit the site logged in again - even if it is a good question).
I'd much rather have a open good question on the site than a closed question, but I'd rather see a closed question than a multitude of poor quality open ones.
Going back to chat again, it really is a good place for the 'fun' things that people seem to nostalgize about and asking/answering those really fuzzy questions that seem to keep showing up about careers and education.
How can I truly prepare for such a test?
when the OP doesn't even specify what the test is? It could be a hackathon type test for all we know. The answers given are 110% dependent on what the test actually is.