No one accepted that one paper at face value, it's just one of several examples of papers and research where actual evidence was presented and explored.

The fact that biolabs exist and leaks have happened in the past are not actual evidence. That lab still exists today and leaks have still happened in the past, does that mean a virus is leaking right now? It's just wild speculation. Wet markets also exist and have been linked to outbreaks of disease in the past. These are reasons for investigations, not for accusations and conspiracy theories.

Gradually, real evidence for the lab leak theory started to emerge. Your parking lot picture and the sick lab researchers are good examples of evidence, even though they're only circumstantial, but none of that evidence existed when people started spreading lab leak conspiracy theories. Those conspiracy theories had no evidence at all.

Even still, investigations were carried out to see if the the virus really was a bioweapon, to determine if it came from the lab, and to see if it came from the market. As evidence that it came from the market grew, the people spouting lab leak conspiracy theories ignored all the evidence for everything else and continued to spread their conspiracies even though the evidence for a natural origin was much stronger.

Any time actual evidence that supported the lab leak theory emerged the media reported on it, and when enough evidence existed to justify the lab leak theory the media took it seriously.