On one hand, it does make sense to lower taxes if taxes are notably harming the economy or harming economic recovery, and under Reagan we DID have a long economic boom. Dropping taxes on the rich by 40% was likely unnecessary, as even ~20% would have been enough for a stable recovery.

The flip side to that is that it installed in Republicans the idea that taxes go down == economy go up, which is nowhere near the truth (as shown by the Kansas Experiment ) and is one of (IMO) the three major shifts in the GOP that has turned them into the absolute shitters they are today. The others FWIW are Gingrich's Contract with America, or more particularly the idea he presented to the GOP that they can never let the DNC have a win even if it would benefit the GOP, and the Southern Strategy.