EDLB
The reasons for bad decisions are varied and many would find them surprising. The number one reason for failure to abort is lack of experience and situational awareness. Other issues are the airlines culture and the extent to which management is vindictive. This can lead to a crew wanting to save the situation, hoping they will get away with it. I used to ask prospective captains how many flights they had flown in a years time and how many diversions. the usual answer is hundreds and none. So given that record, why hesitate to divert if things are questionable. It doesn't happen very often.
All that said, there could be other factors in this case. The initial touch down could have been so hard that there was other damage confirmed or suspected. In which case, continuing the landing would be the most prudent choice. As usual we do not know.