If an effect comes off as you described, I absolutely agree it was poorly constructed.
To clarify, I only wanted to make the point that stooge work was not used in the clip you shared. It is actually a credit to the performers that you would think that, but it is unfortunate that the AGT format does not give them the opportunity to cancel out that theory.
Also, I am not suggesting anything supernatural is going on or that methods were not used.
A skeptic will always have a theory that fits their belief system. They view mentalism as a personal "challenge" and a "puzzle" for them to solve. And they do solve it, just incorrectly 99% of the time. An audience lies on a bell curve - those on the far left are skeptics and those on the far right are believers. There is little any performer can do to change their minds. It is the majority in the middle that typically enjoys mentalism the most.
And you are right - it is not "magic" - it is way better!