The Kulturkampf was not a war between protestants and Catholics
That is partially true. It was primarily part of the struggle for separation of church and state and for supremacy between religion and state that had been going on for centuries throughout the world (and continues to this day). The 'kuturkampf was merely its culminatoion in Prussia and, to a lesser extent, the whole of Germany. It is a fact that the 22 laws enacted as part of the Kkpf were often directed (theoretically, at least) as much against the protestant as they were against the catholic religion.
It is also the case that it stemmed from the wider and ongoing conflict between modernity and conservatism. Its proponents stood for the 'modern way of thinking' as opposed to the outdated and it was opposed as much by conservative protestants as it was by catholics.. Thus, depending on the local circumstances, the Kkpf meant different things to different people. For example, while reputedly Bismarck had little enthusiasm for the liberal secular aims of the Kkpf, he saw it as a useful tool for imposing German nationalist agendas, such as the eradication of Polish nationalism. It is perhaps noteworthy that while most of the 'fires' of Kkpf had been doused by 1878, the anti-Polish elements remained in force in the Polish provinces until WW1. It is, perhaps, in this narrow aspect that one can draw a direct line between Bismarck + the Kkpf and Hitler.
However, reagrdless of the underlying philosophy, it is without a doubt also a fact that the Catholic church and its adherents were the primary victims of the Kkpf. For example while schools in catholic areas were subjected to rigorous state supervision, those in protestant ones were by-and-large left alone. This was, I have no doubt, bacause the Catholic Church was the greatest force supporting those values that the modernist secular state found anathema. For example, ironically maybe, the German nationalist would be offended by the Caholic Church's internationalism in their own back yard but also by it serving as a prop for Polish national identity in the Polish provinces.
The Kulturkampf was a war between 2 religions : the old one ( Catholics and Protestants ) and the new agnostic religion : science .
The educated classes supported science and were hostile to religion .
This is as much a simplistic nonsense as the claim that the Kkpf was a conflict between protestants and catholics. Science is NOT a religion. It is a method for processing information/knowledge. It makes as much sense to claim that there is a war between science and religion as there is to claim there is a war between boiling and vegeterianism. The vast majority of scientists (ie those who use science in their work) were and are are religious. To claim that the 'educated classes' were hostile to religion also seems dubious to say the least, I would like to see the evidence for that.