I think we have to keep in mind that a very significant number of the very high number of people attending Mass each Sunday prior to the Council simply wanted to fulfill their obligation and get the Mass over with. Most Catholics preferred the Low Mass.
They wanted short Masses. I would say of the 90% of Catholics attending Mass every Sunday prior to the Council about 70% were in this category. The Church catered to them and didn't make them feel guilty for liking short Masses and going to confession once a year and Holy Communion once a year. In fact doing these things made them good Catholics. Who can argue with this today given the fact that we've lost this 70% of Catholics who have dismissed the Church and have become "nones?"
The initial changes in the Church pleased them because they could understand the Low Mass in their own language and the Mass was actually being shortened in its Low Form until everyone started going to Holy Communion every week and all were asked to participate, sing hymns and come early (not just prior to the Offertory) and stay until the Mass was finished (not leaving as Holy Communion began).
Asking nominal, but every Sunday going Catholics to do more than just what was obligated was a turn off and forcing them to participate and sing really turned them off. Telling them that what they were doing prior to the Council, the minimal, was not enough offend them and turned them away!
The 12 to 20 % who went to High Mass and Solemn Sung Masses appreciated the Mass for its history and as an art form perfected over 1700 years. They loved choirs that could perform exotic settings of the Mass. They loved Gregorian Chant and Polyphony. They were sophisticated and knew their faith and were comfortable with what they had known all their lives and they loved being different than Protestants, better than them of course.
This group and their heirs today hated the changes and the banalities of the revised Mass, the loss of exotic settings of the Mass sung by fine choirs, the loss of Gregorian Chant and Polyphony and the choreography of the Mass. They hated the loss of being anonymous and the private vertical aspect of the traditional Mass.
What really set off about 80% of the 90% going to Mass though was the renovation of their beautiful Churches to make them look Protestant, almost like Quaker meeting places.
They hated their beautiful altars being torn out. They hated altar railings being removed. They hated lay lectors and Communion Ministers and the dumbing down of the clergy and religious, the loss of respect for these two groups. They hated standing for Holy Communion. They hated folk music. They hated folk groups being in the front. They hated song leaders waving in their face and trying to force them to sing! They hated the Mass becoming to resemble Protestant services. They hated ecumenism that made it appear that the Catholic Church was wrong all along and the Protestant were right.
They hated the confusion that reigned in the Church. They hated it and it turned them off. They didn't know what to hand on to their children and their children's children had no idea of what was lost and no appreciation for what was new.
I would say that Pope Francis wants to get back the 88% of Catholics who do not go to Mass and simply do what we did prior to the Council. Make it easy for them. Give them short Masses. Allow them to go to Confession once a year and Holy Communion as their Easter Duty. He wants to give them a devotional life too. He doesn't want them to be elite Catholics. He wants to get back the obligation only Catholics of yesteryear.