Christians IN GENERAL can be bashed, true, but Catholicism is sole remaining SPECIFIC group that it is OK to demean in modern society and the mainstream media will let you get away with it. If you SPECIFICALLY attacked any OTHER denomination of Christianity, you'd be ostracized for it.
For example, if you said Lutherans "are a bunch of NAZIs, which is not surprised since their founder Martin Luther hated Jews and told his followers to burn their homes", you'd be immediately get called out for that and the media would demand you apologize to Lutherans.
On the other hand, if you said the Catholic Church "is a pedophile cult that its OK to rape little boys because their Pope just promotes that sort of thing", the media would shrug their shoulders and ignore it. Many would even applaud you for trashing Catholicism.
If Luther learned this he learned in through the Roman Catholic church.
From the Fourth Lateran Council 1215...a Roman Catholic council
68. Jews appearing in public
A difference of dress distinguishes Jews or Saracens from Christians in some provinces,but in others a certain confusion has developed so that they are indistinguishable. Whenceit sometimes happens that by mistake Christians join with Jewish or Saracen women, andJews or Saracens with Christian women. In order that the offence of such a damnable mixingmay not spread further, under the excuse of a mistake of this kind, we decree that suchpersons of either sex, in every Christian province and at all times, are to bedistinguished in public from other people by the character of their dress — seeingmoreover that this was enjoined upon them by Moses himself, as we read. They shall notappear in public at all on the days of lamentation and on passion Sunday; because some ofthem on such days, as we have heard, do not blush to parade in very ornate dress and arenot afraid to mock Christians who are presenting a memorial of the most sacred passion andare displaying signs of grief. What we most strictly forbid however, is that they dare inany way to break out in derision of the Redeemer. We order secular princes to restrainwith condign punishment those who do so presume, lest they dare to blaspheme in any wayhim who was crucified for us, since we ought not to ignore insults against him who blottedout our wrongdoings.
69. Jews not to hold public offices
It would be too absurd for a blasphemer of Christ to exercise power over Christians. Wetherefore renew in this canon, on account of the boldness of the offenders, what thecouncil of Toledo providently decreed in this matter : we forbid Jews to be appointed topublic offices, since under cover of them they are very hostile to Christians. If,however, anyone does commit such an office to them let him, after an admonition, be curbedby the provincial council, which we order to be held annually, by means of an appropriatesanction. Any official so appointed shall be denied commerce with Christians in businessand in other matters until he has converted to the use of poor Christians, in accordancewith the directions of the diocesan bishop, whatever he has obtained from Christians byreason of his office so acquired, and he shall surrender with shame the office which heirreverently assumed. We extend the same thing to pagans.
https://www.ewtn.com/library/COUNCILS/LATERAN4.HTM
This council has not been overturned. Roman Catholics are to adhere, or should be adhering to this to this day.