People have diverse reasons for why they pray. For some people they play only when they encounter problems, that is when they see the need to pray. For some others they pray only when they are among their fellow brethren, but they lack a personal altar when they pray even when they are alone.
But for genuine believers, those who know what prayers is really all about, we go to God in prayers because that is the way of life of a christian. We don't pray when we feel like or when we want to. We pray because we have to. Prayers is one of the foundational blocks of Christianity.
Jeremiah 33:3 KJV
Call unto me, and I will answer thee, and shew thee great and mighty things, which thou knowest not.
Calling on God is not a waste of time. There's a lot to be revealed to us by God, but this can only be achieved when we go to God in prayers. There are certain things God cannot reveal to us until we go to Him in prayer. Unwillingness to pray debar us from receiving these things from God.