One of the most common complaints about the current shidduch system is how much predating activity takes place. First the girl is "red" to the boy (or often the boy's mother), who then proceeds to ask a dozen questions and call a bunch of references. If he says yes, the same process is followed by the girl's mother.
This entire process takes a short while, but can delay a shidduch and sometimes (especially in the case of the girl) put one of the parties in a quandary. If the girl has two offers, she has to answer both of them and, in some communities, cannot date both guys at the same time. So let's say guy A is offered on June 1, but for some reason it takes two weeks for the whole predate process to complete. If guy B is offered on June 8, the girl is in a quandary because she won't say no to guy B without knowing if guy A is a worthwhile prospect.
Why so much predate activity? In the Orthodox world dating is costly (and I'm not just talking about money). People usually only date for a few months, partly because the prohibition against physical contact makes dating dangerous. Also, every date is big, everyone takes it seriously, and both parties know that each date can make or break a shidduch. All the hassles and pressure make dating more costly in the Orthodox world. Moreover, divorce is not a viable option for a bunch of reasons, and that makes the need for information even greater.
I think most people would agree that dating is the best source of information about a potential spouse. The longer one dates someone, the more she can learn about him. People can only keep a secret for so long, and people can't cover up their true nature forever. If dating is costly, that makes the costs of information high (meaning that learning about a potential marriage partner is difficult). People therefore supplement their information gathering by the use of proxies, which are other sources of information.
If people can't date, they need to get the information somehow. References are a crude tool, since people's perception of an individual differ. Furthermore, references are usually supplied by the guy or girl, and it's unlikely they will use someone with a negative opinion of them as a reference. So the information gleaned from references will generally be incomplete at best.
People ask questions for the same reason. Someone might ask what shul the guy goes to, and extrapolate from there the guy's hashkafa. Of course, this method is blunt and overbroad. But given the lack of better options, this method is the best way to go. This argument also helps explain why people ask dumb questions. Asking what color tablecloth is used on Shabbos is just a way of finding out a piece of information. Perhaps the questioner wishes to know if the family spends money. Of course there are many other reasons why someone might use an off-color tablecloth unrelated to frugality, but like references and other questions, the answer still generates some information.
This argument also explains why the more religious a community is, the more questions will be asked. When dating becomes more costly, people will ask more questions. And with more questions comes more dumb questions.
The argument against a lot of predate activity ignores the cause of the system: less dating. If people can't date, they have to supplement the information in another way. The questions and references create a cost on the system because proxies are far from exact, and guys will reject a girl who they might have married if they would just have gone out (in other words, predate questions and references are transaction costs on the system). But as long as long-term dating is frowned upon, this system will remain in place.