YES I recently heard an FA say that if you can't lift your carry on into the overhead bin it must be checked. I think their are 2 sides to this, with the free carry on, and the charge for checked baggage I have seen some bags that no way belong being carried on. I think FAs need to handle this situation more delicately. I note on hertz buses in some locations they have signs that say drivers can not assist with any bags weighing over 25 pounds. In my opinion if you are going to charge for checked bags this is another good reason to charge for carry on bags that won't fit under seat for non elite non full fare customers.