This has all been discussed many times on here. But, I'll ask you a question-
How do you know that they don't raise the butt of the cue in the first couple of inches of the final forward stroke, and then hit the cb with a near level cue?
Here's something else for you to ponder-
Some believe that hitting with an upward moving cue does something different to the reaction of the cb. Think about this for a little while. The tip is only in contact with the cb for .001 seconds. That is about 1/8" of travel. Now, for it to be possible for the tip to be moving upwards at contact, that would mean that ones timing would have to be so perfect as to be level on 99.999% of forward travel, and then at the last inch or two of cue travel it would have to be raised. And, still hit accurately where you want to on the cb. Good luck with doing that.
I never said I know they don't raise the butt of the cue. I think when they hit below center, the cue is angled downwards before the final stroke so when they hit the cue ball it is almost level. But when they hit above center it seems that the cue is level before the final stroke.