While I've known those at PBR for many years now (dating back to '05) and currently don't have a good relationship with them based on reasons out of my control, I disagree with the fact that they are all about money. They run a business, they are not a non-profit organization and they promote those who pay for and attend their events as best they can. Their rankings are subjective and if it was based solely on those who contribute the most or play for Top Tier, they would not be as successful as they have become.
It is up to the parents to honestly and unbiasedly grade their children in this regard as far as what to expect from a showcase. Know that an invite showcase will draw more attention from college coaches and scouts rather than a cattle auction type event.
It's great that parents are often more than willing to spend whatever it takes for their child to get that exposure, but there has to be a point where maybe their child has maxed out their baseball abilities at the HS level.
Once parents reach this conclusion and understand the odds of their son becoming a ML player and then being able to honestly evaluate them, it would streamline issues like this.
But to the original point, if a college coach/pro scout is persuaded by PBR rankings, they're not doing their job.
I view it like this...
If there 3 evaluation tools (past results, projected 4 year results, projected 6 year results)
PBR would value them as:
1) Projected 6 year results (40%)
2) Projected 4 year results (35%)
3) Past results (25%)
This obviously varies with how college and pro scouts ranks players.