I came across a video on the news of a severe turbulence that left 10 injured. We can even see the flight attendant being thrown into the ceiling and beverages being spilled on passengers. 

The moment I watched the video I pictured the meal trolley being thrown up on the passengers as well. I google it and discovered that an empty meal trolley usually weights arounds 25 kg. Can you imagine 25kg (if it's empty) being thrown on your legs during a flight? I spent a few hours looking for airplanes / airlines that use meal trolleys on rails and I couldn't find one single picture or information about it. Please tell me I am wrong if there are companies out there using trolleys on rails, but I couldn't find a single one that does. 

So, is there a specific reason not to use meal trolleys on rails? Using rails to move the meal trolley would improve the safety of the passagens and flight attendants and could even create a new way to serve the passagens with automated requests. I made some quick renders to demonstrate this idea.