I can say for me. I don't enter on raiders because:

1. My main job is WHM. I think first thing they'll tell me is to equip AST soul stone. I think raiding guys won't accept a White Mage, specially when he's new at raiding.

2. 200ms lag doesn't help me.

3. I have no experience raiding. So I have no parse in my name, much less an orange parse. And to be even considered viable I must have one of those.

4. Equips: I must have BiS gear. Or I'll be kicked asap. Leniency with gear? Only if I already proved myself.

5. And healer is not even needed depending on the content. Even less the worse of them.