I disagree. I don’t think they are weighing the positive impact on the klal vs. the negative impact on the klal. I just think that they don’t feel that they should advise someone to do something which is not necessarily in that person’s best interest.
Fine. Even if we disagree on the motives (you say it’s because they believe individuals should remain in learning, I say because they believe the Klal should remain in learning), the L’maase is that the Roshei Yeshiva don’t believe that anyone should be dating earlier due to this problem. Not one has put anything into action. So PBA is correct.
P.S. At best, it is the same as the shittah regarding going to the army, where they agree hypothetically that there may be some who should go, but no one has ever been told “go”.