I wish to offer one possible explanation to this.
By putting "Please" in front of a prayer, the help-seeker presupposes that God may not grant him/her His blessings. With the word "Please," his/her prayer becomes an expression of doubt.
We must pray with the assumption that God will grant us His blessings. That's why we always pray in the present and positive tense, as though we have already received God's blessings, and being so, we always accompany our prayers with thanks and praise.
Remember what Jesus said? "... whatever you ask in prayer, believe that you have received it, and it shall be done to you." Yes, there's no point praying if we doubt that what we are asking will not be given to us.
(Sgd) Antonio Jose B. Elumir Jr.
Cebu City