Having bitcoins in hand is not the same as having money in the bank. have bitcoin in hand as if we own we can master all aspects including the market itself. while having money in the bank is only limited to current assets which run out from time to time (consumptive) as long as it is not used, the money is not productive.
I guess when it comes to limits that probably more applies to the wealthy class or when you go to a bank and want to deposit a larger amount, in many countries by now you have to provide a plausible origin of that amount. I can only say that it will be getting worse for sure. The European Union along with many other nations in the world want to get the network tighter and higher in order to fight money laundering.
Whether that is the only reason they have, I doubt it. The problem is not the little dude with a couple of thousand dollars in the bank. The real deal are the big dudes who are hiding millions and even billions. I hope there goal is to catch those too, not just the normal guy.