I disagree. If the pre-OCS PT tests were so valuable, people wouldn't be showing up to OCS and failing. If you can pass prior to OCS there's absolutely no excuse for people being unable to pass once there. So with that being the case, it seems to me that currently they are a waste of the recruiter's time.
And what makes you think that every recruiter actually gave their recruits a pre-OCS PRT? I actually remember asking quite a few of the bunch and they had openly admitted that their recruiter fudged numbers or didn't test them at all. Obviously not accusing the recruiters, but its not the first time I've heard of them NOT doing it. Even my recruiter said he knew of others that would just fudge numbers to get their kid in the program or didn't test them at all.