The reason behind this policy is pretty simple: safety. By only allowing clear bags, security personnel can easily see what's inside without having to rummage through your stuff. It's like going through TSA at the airport, but less stressful, hopefully!
But, what if you have a fancy camera or a tablet you want to bring in? Don't worry, you can still bring those in, as long as they're not in a prohibited bag. Just be prepared to take them out of your bag and send them through the X-ray machine separately. It's like sending your laptop through the scanner at the airport, no big deal!
