That is my whole point. JPII was endorsing the act of worshipping false gods.
"Endorse" implies promoting. Thus an athlete "endorses" a brand name tennis shoe and encourages others to buy and wear it.
That is not what happened at Assisi. The Pope was not encouraging, endorsing, promoting that people join other religions or worship false gods. He preached Jesus Christ at the meeting itself. Obviously through this and countless other of his writings and the fact that he is POPE people can plainly see he is Catholic (sedes aside) and wants people to be Catholic. Obviously we believe he wants people to be Catholic as sort of a pious desire as opposed to Trads who believe it is a necessity.
One can interpret Assisi to mean these things, but I think they have to strain to do so. In fact Assisi appeared to give this impression, but in reality conservative Catholics and even liberal Catholics know the Pope was not actively promoting the joining of non-Catholic religions. If he really did so, don't you think the liberals would be crying this from the roof-tops? Instead they were probably PO'ed he didn't join the pagans in worship.