Actually, many people have been making the same mistake. That is, all the efforts that they put into the preliminary practice only go to fulfill the requirement of certain amount of mantra recitations, missing the essential points of the teachings instead. To handle the practice this way is a foolish waste. The saving measure is to carefully examine the motivation for whatever we do, be it undertaking to practice to supreme Vajrayana, the foundational five preliminaries, or just doing daily activities.
~Depicted from The Right View