But what’s the reason for all this? Why did the Church always fight resolutely against such trends in the past, only to succumb to them to a large degree this time? There are, I believe, several reasons.
The first one is the seductive allure of the Anglo-Saxon liberalism. The Anglosphere has been at the undisputed forefront of Western civilization for almost a century now, and especially after WW2. Thus, it’s nearly impossible for any intellectual, Catholic or not, to avoid the temptation to succumb to its intellectual trends, rather than to stick to traditionalism and be branded a troglodyte by the fashionable opinion. So, we’ve ended up in a situation where the Church leaders, all the way up to the Pope, are bending over backwards to be as PC as possible on all questions except those few ones where it would mean out-and-out heresy or apostasy. Thus, they’ll hold the line when it comes to, say, abortion, gay marriage, or woman priests, but they’ll frenetically try to make up for it on all issues that the Church has traditionally considered as a matter of free personal opinion and a free choice of the secular authorities, such as e.g. mass immigration, death penalty, or the policies and attitudes towards Islam. Of course, like all appeasement, it only feeds the beast and creates further pressure to abandon the traditional doctrine on all other matters where it might conflict with the PC worldview.
The second one is the frog-boiling principle. The modern PC liberalism has acquired its present extreme characteristics only slowly and gradually. There was no single point at which mainstream politicians and public intellectuals started advocating things grossly incompatible with the Catholic faith, which the priests and bishops could then recognize as the time for a decisive break with them. (Like, for example, the Church in Eastern Europe suddenly found itself under an openly hostile regime in 1945.) Rather, the priests and bishops have stuck to their prominent social roles, even if this required tolerating (and endorsing by silence) more and more grossly heretical and sinful views among the social elite whose part they wanted to remain. Thus, we have slowly drifted towards a situation where Catholic bishops cavort with pro-abortionist politicians without daring to mutter a single word against their views, and a priest gets arrested for protesting against abortion on the campus of a supposedly Catholic university, lest the reverend fathers running it might be deemed uncouth by their social peers. On a more mundane level, the same prideful lust for social prestige leads to the disgusting modern church architecture and art that will win praise by the modern art establishment, even if it’s at the same spiritual and aesthetic level as an abandoned warehouse. (How anyone can have any respect in the first place for this bunch of obnoxious poseurs and charlatans and their nauseating output is beyond me, but that’s a topic for some other discussion.)
The third one is that many Catholic hierarchs, theologians, and other intellectuals have committed the same ignorant errors that have pushed the Mainline Protestant churches into de facto dechristianization. By this I mean the naive conflation between the traditional Christian virtues of charity, mercy, justice, and love of neighbor and the modern PC/Universalist sugary liberalism, and the similarly naive conflation between traditionalism and fascism/Nazism. Thus, many of them actually believe that even the most abominable and extreme left is preferable to even moderate traditionalism. These days, among liberal Catholics, one will certainly draw much more controversy by being a fan of the Tridentine Mass than the Clown Mass, and one will be considered far more evil for giving un-PC comments about issues such as multiculturalism than for outright heresy and apostasy aimed at making one’s views more PC. For various reasons, some of them discussed above, the present power of such currents of thought among Catholics, both laymen and clergy, is at a historically unprecedented level, as well as the favorability of the surrounding environment for their growth.