Where is the mekor to “celebrate diversity”? Sounds like that one came from the M side of MO.
As for Sinas Chinam, it’s only “chinam” if there is no reason for the sina. But if it’s, for example, to call out shmad for what it is, that doesn’t sound like chinam, to me.
As it happens, I agree that within the Torah’s parameters, diversity is a nice thing. But when halacha is breached then it’s a terrible thing.