I think 48 hours is more like "if all goes according to plan" situation, and even in that it takes 24+ hours for sure, and less than 48 hours, there aren't that many cases you get it back in a few hours, that just doesn't happen.
However, if things do not go according to the plan, then we are talking about a situation where it can easily take longer than 48 hours, and until what is wrong gets figured out, it could take as long as a week. I am not against these, I had it happen to me before and I was fine about it for two reasons. First of all duelbits is a trusted and well liked place, secondly I did not do anything wrong so I had nothing to worry about. Combine those two, and you know there is no problems.
I know it can take longer than 48 hours for various reasons but not a lot of people are patient nowadays and we all want to have things instantly. Especially, if you are awaiting money and your KYC keeps lingering, than you can get impatient.
Not that I'm against with but yeah you are correct, there are impatience people who will push their way to fasten the process, but like what the post above you said.
If you know that you don't do anything wrong and you trust the site that you are playing, then there's nothing to
worry, you can always ask the support and ask for some assistance or update regarding to your submitted documents.