For example, I encounter the argument described above, that "other side are ignoring obvious facts, and so failing to behave rationally, because they're blinded by their ideology" very rarely, even in political discussions. Politicians saying such things would find it hard to negotiate with other politicians to form a government, and are mostly smart enough to not say such things. They would have no difficulty admitting that other politicians/parties behave differently simply because they have different goals (they represent the interests of a different set of voters), while still acting on almost the same set of evidence.

1. I would expect that some parties know that they will never form a coalition with certain other parties. If so, do these "incompatible pairs" show more inclination to accuse each other of ideological blindness?

2. It sounds like people within your country are pretty ideologically homogeneous. But you must differ ideologically from other countries. Your homogeneity leads me to expect that your country is relatively small. This, in turn, means that, relative to a larger country, you probably have less control over the policies of other countries, but those policies have a greater effect on your country's interests. Does the "ideological blindness" explanation sometimes get invoked when talking about why people in other countries chose those policies? (For example, I have seen some people in European countries blame some of their economic problems on a world-wide economic meltdown caused by the free-market ideology of the United States.)