Misty mountain is constantly a target for terrestrial and celestial threats. I think the tree is trying to protect weak creatures from facing a demise they otherwise might not. Think about when the main weaker cast (Baldy, Golden Monkey, Boar, previously White Tiger) ends up putting their lives on the line. One, their deaths would devastate the tree and the other creatures (mostly the weaker creatures that have been around since the beginning). Two, everyone or at least the tree or Big sis ends up clamoring to save them. They don't always do that, but they do if they really feel like the weaker one will die. That puts the other creatures at risk because they're rushing into a battlefield that could be using the threat of killing a weaker creature to capture/take advantage of the emotions of the stronger creatures. I feel like him saying the weak don't belong really is just a call to action for the weaker creatures to get stronger and an attempt to protect the creatures that are too weak to survive the battles of misty mountains.
"the weak don't belong in misty mountain" says the tree/human that was also weak. I don't like how he's turning into those typical unlikable power hungry main characters that only cares and values strength. Him saying that just doesn't sit right with me and made me feel like dropping this bs immediately and never read it again unless he gets some amazing character development. But oh well,I should've never expected so much from a chinese power hungry story that's hella racist and only cares Abt making their beings stronger and white humans stronger,cause why TF are the black male characters always ugly while the female characters are always overly pretty with oversexual body proportions?? They draw most male characters like a bunch of monkeys. But Anywaysss we'll see if the characters finally get some good character development soon.