It is a fact that humans are omnivores.
BUT: it's also a fact that most humans in modern society eat WAY TOO MUCH meat.
It's unhealthy.
If a human were to eat only vegetables, fruit, seeweed, etc ... he would be very healthy.
If a human were to eat only meat ... he would be very unhealthy.
Meat can be an addition to a healthy diet but it can't be the base of one.