They were not necessarily bad science, rather very desperate companies looking for the holy grail, trying to get there taking shortcuts. They have taken drugs into p2's were the p1 clearly was a failure or take them into p3's based on flimsy data, grasping at straws.
Hence this PK/PD analysis is so important to get it right. It is all about having realistic goals to achieve in a p3. This will lead to a quicker approval, if the results can be reproduced.