Catholic exodus

Many theories have been proposed for the demographic decline of Catholicism, and no doubt there are multiple factors, but I wonder if one factor is that many Catholics can't take aspects of traditional Catholic ethics seriously, because some of them are so arbitrary. The official policy on contraception is routinely flouted. Couples find it gratuitously onerous, and the rationale was always ad hoc. 

Likewise, how many Catholic boys ever took the masturbation taboo seriously? There may have been a fraction of very devout Catholic boys who tried to abide by the strictures, but I suspect most Catholic boys ignored it. 

Same thing with mandatory priestly celibacy. It was never realistic. These are policies that cut too much against the grain of human nature. 

By the same token, divorce used to be illegal in Catholic countries, which created many unnecessary hardships. Admittedly, many couples divorce from the wrong reasons, but there are justifiable reasons as well. I read about an Irish Catholic family back when divorce was illegal. The husband/father/breadwinner deserted the family. That plunged the family into grinding poverty because his wife couldn't legally divorce him and remarry. 

The bottom line is that when the Catholic church has ethical policies that are arbitrary, many Catholics ignore the policies.  But that means they can't take the authority of their denomination seriously. Yet once that happens, there's no stopping the drift.