There's your answer. Quote from Dolan's article.
One of the arguments against sex before marriage was possible pregnancy and/or disease. A practical argument but not a moral one since both may be prevented with care.
So is sex before marriage primarily a moral issue or just a matter of “virtue and responsibility” that might be met by engaging in so-called “safe sex”?
If the first then males must be brought into the picture instead of telling some teenage girl, “Don't get pregnant” as if it's something she does all by herself or is solely responsible for.
If the latter then science will determine morality by how well it prevents a few of the results of immoral acts.
Dolan says, “”Abstinence before marriage is the only sure way to avoid pregnancy and disease, while also allowing minors to practice virtue and responsibility”.
The young say using reliable birth control meets his criteria without the abstinence. And since Dolan nor any other priest will penalize fornication what is he really saying except that abstinence works better than birth control (not in question).
On what basis is he making an argument against sex before marriage? Primarily the use of birth control as immoral rather than fornication as being immoral.
And it's failing.