Because it is not a big issue to Protestants. As far as who is 'well informed' and what is 'dreck', that is nothing but your biased opinion and only serves to be inflammatory. As far as me saying 'the Church cannot change people's minds', I never said that. I just don't see fights between denominations or Catholics vs. Protestants as being God's will. I view us all as brothers and sisters in Christ, and most of the differences we bicker over mean little to God.
I enumerated the elements that point to the former Catholic being badly informed: the ideas that the Church does not teach or know the scripture, that the sacraments are rituals, that obedience to rules saves, that personal relationship with Jesus cannot exist in a liturgical hierarchical church -- all come from ignorance of Catholicism.
Do these differences "mean little to God"? The scripture tells us that they are of great concern to God: St. Paul was furious that there were divisions in Corinth; Christ prayed fervently that we be one as His Father and He are one. Surely we can cooperate, for example, in pro-life politics, and very much in Protestantism remains Catholic and is therefore authentic Christianity, even though it is rarely acknowledged. However, the religious belief dictates culture and culture drives politics; it is hard for me to observe the centrifugal trajectory of Protestant Christianity in the past few centuries and not to expect even weaker bonds between us in the future.