Its very simple: Jesus claimed to be God, and specifically instructed that prayer be offered in His name. (John 14:13, 15:7, 15:16 16:19 & etc.) Praying in Jesus' name is an integral part of Christianity, from Jesus until today.
If Jews, Moslems or people of other religions don't like that: GET OVER IT. IT'S CALLED TOLLERANCE!
As a Christian I am deeply offended by neutral, ecumenical, namby-pamby prayers--they disobey the commands of Jesus, and they don't reflect reality...
You would say this even though you were making a prayer to a group of people which had Jews in addition to Christians?
I love it! If you don't like potatoes, you are still going to eat nothing but potatoes for the rest of the year --- get over it!
What do you mean, why? 'Cause I said so! Don't you know, this is a democracy, damn it! Seargant, take out this man and shoot him: we don't want him to spoil this democracy of ours.