It is no secret that the NFL combine matters. We can whine about examples where it leads to false positives or negatives but holistically, the combine matters. NFL teams care and so should you. Now, does having a BAD combine disqualify a player from being good? It certainly can but doesn't entirely. The two most likely outcomes from the combine are players that were borderline prospects perform so poorly that they relegate themselves to late-round flyers and average (and/or intriguing) prospects have completely nuclear performances and raise their NFL draft stock a few rounds.
Rarely will we see players expected to go in the first few rounds have horrible (or unexpectedly great) combines and therefore, as long as those players are hitting the correct thresholds, there really is not much to react to.