There are entire economic schools dedicated to what is referred to as 'trickle-down' economics. To say that it has no academic integrity is to ignore huge swathes of peer-reviewed literature. To assign an intention on those that believe in the theory behind it is really quite ridiculous.
The problem isn't that it doesn't have any academic integrity but that the application of it is limited in scope and the politicians that promote it either don't acknowledge the limitations or promote the limitations as a feature. You can encourage the rich to spend the additional money they now have due to tax cuts but you can't force them to spend at all, you can't force them where to spend, and you can't force them to spend in a way that promote growth in the middle and poor classes. It's a "you can't push on a string" type policy, so making it a "go to" economic policy at a federal level is inadequate at best or nonsensical at worst.