Having the same trouble as Long Yangjun, Li Yao was quite empathic.
If the unpredictable 'Earth' was placed right before him, yet somebody stopped him from entering it for exploration, he certainly would have gone mad, too.
However, a thousand people were involved in Operation Archeology, and hundreds of times more people were outside providing back up. There were billions of civilians on the entire planet of the Ancient Sages Sector.
If a few giant crabs ran loose in their carelessness and created countless cruel, heartless members of the Pangu Clan, the consequences would certainly be dire.
Not only would the thousand explorers likely be killed, even the entire Ancient Sages Sector or the federation outside of the dark nebula could be swallowed!
They had to be responsible for everyone's life. It was not the time to be self-willed. Carrying a burden who was heavily wounded would be a great weakness for the team in any place.