Why should I wait to recoat when the last coat is dry and not tacky?

For the love of all that is good, DO NOT RECOAT WHILE THE LAST COAT IS TACKY. The previous coat MUST be dry to the touch before you recoat or else you run a very high risk of the coating bubbling and possibly even peeling off. And if that happens, YOU WILL HAVE TO SANDBLAST IT OFF AND START OVER. Seriously, do not do this.