(namely Queen Isabella and Pius XII, in particular).
Why bother? This is what I don't get. There are plenty of Catholics, plenty of Catholics who aren't saints, plenty of Popes who aren't saints. Plenty of Catholic rulers with mixed records who aren't canonized saints, and ...that's okay. In relation to Pius XII, as one commentor pointed out, it's barely half a century since his death...what's the rush? This whole business of sorting out the historical record of the Church, and particularly the Vatican in the years leading to, during and after World War II, would be far less contentious if it weren't tied to even the hint of canonization.
Saints are always complicated people with flaws that they would be the first to tell you about, but a situation like this is different than considerations of Escriva's temper or Mother Teresa's doubts. As the Commonweal article pointed out, Pius XII made decisions that were often the best he could do in a terrible situation and some that were rooted in more parochial concerns. And there's a lot we still don't know because not all of the archives have been opened.
But why the push for canonization? Who is it coming from? Is it coming from the masses? Is there a huge cultus forming around the cause?
Not that I've heard of. It seems as if the push for Pius XII's canonization is coming from the Vatican, for whom the canonization would function as a blanket exoneration of Church failures during this period.