Ok, let's stop the guessing and get to facts:
1) The thinner the air, the less the turbulence. Thus at higher altititudes, where the air is thinner, the less likelinhood of weather turbulence. Just because you had a rough experience on one flight, Cx340, it does not make it the rule for all flights!
2) The colder the air, the less turbulence. Hot, humid air disturbs the weather. The higher you fly, the colder the air. Now don't start telling me that there is no turblence during a blizzard. Of course there is!
3) Turbulence as we experience it in today's jets (and alos in today's pressurized props) is not compararble to the unpressurized aircarft of yesteryear, which usually flew below 12,000 feet. Pax were subjected to vibrations, buffetting, and loud noise. I don't know how they used the luzury facilities, as the original poster here aksed! Today, we often hear pax talking about how sever the turbelence is when in reality it is often classified as "light turbulence."
17 year airliners.net vet! 2000-2016