Just because thee system said that claiming the ownership of this dimensional crevice was worth it was not the only reason for his decision. There was an assumption in his head about the dimensional crevice.
'Since even the powerful cultivators wanted to destroy it, then there must be some reason for their actions. Either it has something valuable inside it or they must have feared the previous master from growing powerful,' Ajax silently muttered in his head about the dimensional crevice.
In general, a very powerful cultivator didn't bother to kill someone with low cultivation with no apparent reason. In their eyes, others were just some ants trying their best to survive.
So, Ajax thought that since some powerful cultivators tried to destroy the dimensional crevice and killed its previous master. Ajax felt that there was something that attracted the attention of those powerful cultivators.