The thought of Spanish Church having the very same dominant position during those last centuries is quite simple, but understandable. We shall have proper occasions to discuss about, so I shall not focus this on that.
My opinion is that all we have, for bad, is deserved. For the decadence of Spain, ironically, starts with the king that we consider one of the last optimus ones (Charles III) and there are quite a lot of funny things that you might not see as fun as I doth. But, then, we are at the first point: not focus on...
The disconnection between Alt Church (I mean, bishops and every important clergy) and People comes from the 19th Century. The common error is to think Alt Church is The Church. In my town (the one which most of my ancestors come from), a bit traditionalist town, there was a lack of Christianity, because of that disconnection, at the beginning of 20th Century, for they were merely abandoned as since the couple of desamortizaciones
(confiscations) that affected those of whom had no house and lands of their own, supposed that the consecutive consecuted clergies sent to that town were no longer rooted in a lot of cases, and that was noticed, by the way. No enlacing believers with beliefs is a very good way to lose beliefs either believers, sometimes both. And that is what was happening from approximately 1880s to 1950s. The fact that stopped this faith drain was, ironically, that they started sending "rebel clergies" to my town (as a punishment for them), who helped peasants in a lot of ways. Curiously, consequently, the embers of faith were rekindled. We the People are quite a little bit selfish, we just need some quid pro quo. Bad clergies are the worst enemies of their very cause, as you rightly have pointed.
I do not think it is reversible in Spain, because of the lack of time. Some Iparraguirre's verses come to my mind. I am sad for we are not to survive, as we are at the point that marks the border. We are not growing in population, and we are being replaced; it is the end of the world as we know it... and I should feel fine. hahaha There is reversibility only if the Americans win the replacement to the non Spanishish
ones. Yet I do not think so. We were, still are, but will not be. You are talking to a legend.
So, if you ask me how to reverse the situation in other countries, I can answer what I think that can be done. Stay firm, as I said a couple of days ago, act like Catholics and help your equals and those gentle gentiles. Do not surrender you beliefs to corrupt clergies and purge the purgeable, even if it is supposedly consecrated to God. There is my response to what can we do against bad clergies, so. Fight corruption from inside, know that Unity makes strength. You can think that the lack of consciousness that you see in Spain shall not ever get into Poland, but I am afraid it can and it shall, if Poland loses the principles that make Poland Polish. I say that because I like Poland, I am not very kind and I should not tell you what I am telling if I did dislike your country, as I could enjoy what I would be currently enjoying if I did not like Spain.
I am sorry this is a very extensive matter that I cannot afford as properly as in Spanish.