It is a big bummer for sure.
What you said is accurate. The 3 criteria for interview invites is, in order of importance: Sci GPA/Last 45 GPA, GREQ, PPI. That's it. I've spoken with their admissions department, and they said were very proud of how streamlined (actual word used) their admissions process has become. Maybe it's just me, but I'm not sure streamlining admissions for a 4 year professional school is something you want to make your top priority. Call my crazy, but if I were looking at applicants, I might actually want to use a certain degree of care in selecting candidates, rather than running a computer algorithm.
Yes, GPA and GRE are good indicators of whether or not you'll be successful in veterinary school, but that's not the point here. UC Davis (and apparently LSU) fail to understand that they're not the ONLY factors, and I feel that it's going to hurt their futures as institutions.
Again let me reiterate, congratulations to all of those who received interview invites, you definitely deserve it! My beef is with the school, not you guys.